Understanding and Reacting to Relapse: Considerations for Practitioners

Abstract

Severe challenging behaviors, such as aggression and self-injurious behavior, have a high comorbidity with autism spectrum disorder (ASD; Hill et al., 2014; Soke et al., 2016). Although we have effective assessment and treatment procedures for severe challenging behavior, the relapse of severe challenging behavior following effective treatment is highly prevalent (Briggs et al., 2018; Falligant et al., 2022; Haney et al., 2022; Muething et al., 2021). Effective in 2025, the Board Certified Behavior Analyst (BACB) Test Content Outline (TCO; 6th ed.) includes a task-item requirement for Board Certified Behavior Analysts to plan for and attempt to mitigate possible relapse (BACB, 2022). Thus, it is important for practitioners to understand the variables that impact relapse of severe challenging behavior, and it is critical that they have access to tools to help them in preparing for and reacting to relapse in practice. The purpose of the current paper is to provide (a) a consumable framework on relapse for practitioners and (b) considerations for practitioners on managing relapse when it occurs.

Relapse is broadly defined as the return of previously eliminated target behavior and can come in different forms such as spontaneous recovery, renewal, resurgence, and reinstatement (Lieving et al., 2004). Several recent studies have demonstrated that the relapse (e.g., renewal, resurgence) of severe challenging behavior (e.g., aggression, self-injurious behavior, property destruction) is highly prevalent in clinical practice (Briggs et al., 2018; Falligant et al., 2022; Haney et al., 2022; Muething et al., 2021). However, these studies evaluating the prevalence of relapse have all taken place in highly specialized (e.g., hospital-based inpatient or day-treatment) programs focused on the assessment and treatment of severe challenging behavior. The prevalence of relapse in less specialized and more common service delivery settings remains mostly unknown. Although prevalence estimates have largely been derived from highly specialized settings, it's very likely and plausible that relapse occurs in less-specialized settings (Kimball & Kranak, 2022). After all, learners receiving treatment in highly specialized settings come from and are likely to return to less-specialized settings. In other words, practitioners are likely to encounter relapse at some point in their careers. Additionally, severe challenging behavior has a high comorbidity with autism spectrum disorder (ASD; Hill et al., 2014; Soke et al., 2016), and most service delivery settings for ASD are most likely less-specialized treatment settings.

It is important that practitioners understand the variables that impact the relapse of target behavior such that they can prepare for and attempt to mitigate its occurrence. In fact, effective in 2025, the Board Certified Behavior Analyst (BACB) Test Content Outline (TCO; 6th ed.) will include a task item that requires Board Certified Behavior Analysts (BCBAs) to plan for and attempt to mitigate possible relapse (BACB, 2022). Thus, it is critical that practitioners are prepared for this TCO requirement and have access to tools to help them in preparing for and reacting to relapse in practice. The existing relapse literature focuses primarily on recommendations based on interventions from specialized, hospital-based treatment programs (e.g., multiple schedule functional communication training [Mult FCT]; e.g., Falligant et al., 2021). However, Mitteer et al. (2024) recently reported that the common procedures used within this literature, such as Mult FCT, may be used less frequently within less-specialized settings and when treatment is designed by masters-level BCBAs. In the United States, masters-level BCBAs make up over 95% of those who may practice independently (BACB, 2024). As such, BCBAs may benefit from additional resources surrounding how to identify and manage the occurrence of relapse of severe challenging behavior in practice.

One such resource, by Kimball and Kranak (2022), focuses on renewal. Specifically, the authors provide practitioners with six key considerations surrounding the phenomenon of renewal that may occur when recipients of applied behavior analysis (ABA) services receive treatment in various settings and by various interventionists. While valuable, this resource focuses on only one form of relapse. There are additional resources available that provide recommendations describing other forms of relapse (e.g., resurgence and reinstatement) and mitigation strategies for relapse (Kimball et al., 2023; Kranak & Falligant, 2023; Saini et al., 2024; St. Peter, 2015), but the current paper aims to encompass multiple forms of relapse and extend beyond relapse mitigation strategies. The purpose of the current paper is twofold. First, the paper is intended to provide practitioners with a consumable framework on relapse to consider when working with individuals who engage in any level of severe challenging behavior. This framework is focused on enhancing practitioner understanding of relapse and circumstances that may lead to its occurrence. Second, this paper provides concrete options for practitioners to consider for reacting to relapse when it occurs.

Understanding Relapse

Reducing and eliminating severe challenging behavior is like reducing and maintaining weight (A. Zangrillo, personal correspondence, May, 2019). Weight loss is typically achieved by consistent implementation of healthy eating and exercise. After achieving a desired, healthy weight, one must uphold a healthy eating and exercise routine to maintain the weight loss. Following discontinuation of that healthy lifestyle, the undesirable weight gain is likely to return. The same pattern holds true in the treatment of severe challenging behavior. We can only reduce and maintain severe challenging behavior at low or zero levels by consistently implementing the prescribed behavior intervention plan (BIP; e.g., Falakfarsa et al., 2022). When a practitioner or caregiver stops adhering to the intervention plan, or an intervention plan is not adequately developed (e.g., not function based), severe challenging behavior may return following treatment.

Given the prevalence of relapse, the ease with which it can occur, and our desire to always achieve sustainable treatment outcomes, it is critical that practitioners understand several variables surrounding relapse to successfully plan for and react to its occurrence. Specifically, we recommend that practitioners first ensure awareness of the (a) different types of relapse and variables that may lead to their occurrence, (b) potential repercussions of relapse if it does occur, (c) individual client considerations, (d) safety precautions, and (e) importance of data collection and ongoing data review. We describe our recommendations regarding relapse awareness in the following section.

Not All New Severe Challenging Behavior is Relapse

Prior to discussing the different forms of relapse, it is important to briefly review what is not relapse. After familiarizing oneself with all the forms of relapse, it may be possible for practitioners to begin seeing all forms of severe challenging behavior that occur following treatment as some form of relapse. However, practitioners must keep in mind there are other reasons for severe challenging behavior to occur, even if topographically similar, that are not due to relapse. For example, if a practitioner overlooks the best practice recommendation of considering a client’s preferences in the treatment design, such as offering choices (e.g., Rajaraman et al., 2022; Shogren et al., 2004), an aversive condition may be created, thereby evoking severe challenging behavior. In another example, the function of severe challenging behavior may change, rendering the current treatment ineffective and evoking severe challenging behavior. By avoiding overgeneralization, practitioners will be able to readily recognize what is relapse and begin considering the possible repercussions.

Types of Relapse

One of the first steps for practitioners seeking strategies to potentially mitigate and effectively react to relapse includes ensuring awareness of the different types of relapse that may occur to better predict and plan for potential situations that may lead to relapse. Although existing relapse review papers provide thorough overviews of the different types of relapse and supporting research on mitigation strategies (e.g., Kimball et al., 2023; Wathen & Podlesnik, 2018), we seek to provide examples that may be more common and familiar to the everyday practitioner. Table 1 contains definitions and examples of each relapse type. In standard research of relapse, researchers use a three-phase arrangement to determine under what conditions treatment maintains or relapses (Wathen & Podlesnik, 2018). Target behaviors (e.g., severe challenging behavior) result in reinforcement in Phase 1. In the clinical setting, this likely would be the baseline phase. In Phase 2, an intervention is implemented to reduce the target behavior (e.g., differential reinforcement, extinction of the severe challenging behavior). Phase 3 consists of a modified reinforcement or stimulus condition, and this phase tests under which conditions and to what extent treatment maintains (i.e., continued suppression of severe challenging behavior) or relapses (i.e., previously extinguished severe challenging behavior recurs; Kimball et al., 2023). In the clinical setting, Phase 3 may represent planned modifications, such as generalization probes or reinforcement schedule thinning, or it may represent unplanned changes. If practitioners understand and monitor the conditions under which relapse occurs, they may utilize similar arrangements to prospectively or retrospectively determine what type of relapse occurred and react accordingly.

Table 1.

Relapse Definitions and Examples

Relapse Type	Definition	Example
Resurgence	When there is a worsening or discontinuation of reinforcement for alternative behavior (Lattal et al., 2017; Perrin et al., 2022)	A caregiver is in on a work phone call and cannot reinforce the learner's request. The lack of reinforcement for the request results in resurgence
Renewal	When there is a stimulus context change, but in the absence of a change in the reinforcement contingency for appropriate behavior (i.e., treatment integrity remains high; Podlesnik et al., 2017)	The primary technician is sick, so a novel technician works with the learner instead. The introduction of the novel treatment implementer constitutes a context change, which results in renewal
Reinstatement (Response- Dependent)	When the functional reinforcer is delivered contingent on severe challenging behavior following successful treatment (Kranak & Falligant, 2023)	A teacher provides the functional reinforcer following severe challenging behavior in class instead of withholding reinforcement until observing the communicative response. The target response-contingent delivery of the functional reinforcer results in reinstatement
Spontaneous Recovery	When there is time away from treatment sessions after the extinction of the previously reinforced severe challenging behavior despite no changes in reinforcement conditions for the alternative response, context, or reinforcement conditions for the severe challenging behavior (Wathen & Podlesnik, 2018)	A client returns to treatment sessions following a long holiday weekend. The extended break from treatment sessions and exposure of severe challenging behavior to extinction results in spontaneous recovery

Resurgence

Resurgence occurs when there is a worsening or discontinuation of reinforcement for alternative behavior (Perrin et al., 2022). In the three-phase arrangement described above, Phase 3 consists of extinction or worsening conditions of reinforcement for the alternative behavior (Lattal et al., 2017). Examples of when resurgence may occur include when reinforcement schedule thinning occurs too rapidly, when there is an omission of the reinforcer due to caregiver treatment integrity errors, or when the magnitude of the reinforcer does not abate severe challenging behavior (St. Peter, 2015). In a home, a school, a day program, or the community, caregivers may not deliver reinforcement for alternative behaviors at the same schedule density, or as frequently, as in clinical practice. For example, caregivers may not attend to each communicative response emitted. This lack of reinforcement for the communicative response may occur when the individual asks for a preferred item when the caregiver is in the shower, in the middle of a work call, or interacting with another individual in the home setting.

Resurgence may also occur when the individual emits the alternative response at a high rate, such as an individual requesting for unhealthy snacks frequently and the caregiver cannot provide the requested food item due to health and safety limitations, or limitations imposed by other stakeholders (e.g., funders for items, program policy restricting intake of specific reinforcers, etc.). Another situation in which resurgence can occur is when the magnitude of the reinforcer decreases to the point in which it no longer abates severe challenging behavior. For example, this may occur when an individual requests for a break from a task and is provided a brief break (e.g., 30 s) rather than a longer break (e.g., 2 min) due to time limitations, such as getting the individual ready to attend an appointment on time. There are additional situations found in the literature that may engender resurgence, including the loss of the communication modality (e.g., picture exchange card; Randall et al., 2021) and when caregivers cannot reinforce an appropriate request due to a language barrier (Banerjee et al., 2022). Unfortunately, recent prevalence research suggests practitioners may observe resurgence during reinforcement schedule thinning following FCT in approximately 76%-91% of cases (e.g., Briggs et al., 2018; Kranak & Falligant, 2021).

Renewal

Renewal occurs when there is a stimulus context change, but in the absence of a change in the reinforcement contingency for appropriate behavior (i.e., treatment integrity remains high; Podlesnik et al., 2017). In reference to the three-phase arrangement, Phase 3 would mark a specific stimulus context change that may be intentional or unintentional. The stimulus context change can be a change in the person implementing treatment or people present, a change in the treatment setting such as a transitioning to a new location or familiar location, or a more subtle change in the environment such as a rearrangement of materials in a location. Some common examples of situations in which renewal may occur can include when the individual has a substitute teacher at school, a new staff member is hired at a residential facility, the individual goes on a community outing, changes classrooms or teachers at the start of a new year, changes schools or day programs, or returns home following treatment. While this list is not exhaustive, it exemplifies a variety of potential context changes in which renewal may occur and highlights the need for strategies to manage relapse when it occurs.

Context changes that result in renewal might be intentionally programmed changes or possibly unprogrammed changes to the environment. Programmed context changes may include generalization testing, a learner entering a new classroom at the beginning of a school year, getting a new job support coach, returning to the group home after an overnight family visit, or going from one parent’s home to the other parent’s home. In contrast, unforeseen changes in the context of treatment likely occur quite often during the treatment of severe challenging behavior (Kimball & Kranak, 2022). For example, the primary behavior technician is sick or recently resigned from their position, and a substitute technician temporarily implements treatment. As another example, during home-based services, treatment usually takes place at one caregiver’s home (e.g., the client’s mother’s home), but because that caregiver is not available due to an emergency, the treatment session occurs at another caregiver’s home (e.g., the client’s father’s house). We view these situations as unprogrammed context changes, and practitioners should expect renewal to occur. Prevalence data suggest that renewal may occur in approximately 59%-69% of cases when changes to the treatment setting or implementer occur (e.g., Falligant et al., 2021; Mitteer et al., 2022).

Reinstatement

There are two types of reinstatement. Response-independent reinstatement occurs when severe challenging behavior recurs following delivery of reinforcement provided independent of the individual’s responding (DeLeon et al., 2005). For example, caregivers may provide reinforcement non-contingently, giving free access to the reinforcer. This free delivery of the reinforcer may lead to response-independent reinstatement. Alternatively, response-dependent reinstatement may occur due to a lack of adherence to the behavior plan for relevant caregivers or stakeholders, leading to the caregiver or stakeholder inadvertently delivering reinforcement contingent on severe challenging behavior (Kranak et al., 2022; Mitteer et al., 2021). For example, let’s say an individual emitted an alternative response, but just prior to receiving the reinforcer, the individual also engaged in severe challenging behavior. The caregiver may not have observed the severe challenging behavior or may have observed the severe challenging behavior but provided the reinforcer because the alternative response had been emitted. These are commission treatment integrity errors that may lead to response-dependent reinstatement (Kranak & Falligant, 2023). Other common examples of commission errors include when the individual and caregivers are in a situation in which the severe challenging behavior must be suppressed immediately, such as paying at the grocery store, or when the individual is engaging in aggression toward another resident of a residential facility. Commission errors may also occur when a caregiver or stakeholder is attempting to avoid escalating the situation further by withholding the reinforcer, and therefore knowingly provides the reinforcer despite the occurrence of severe challenging behavior. For the purposes of this paper (i.e., the relapse of severe challenging behavior, specifically) we will primarily consider response-dependent reinstatement. Practitioners should be aware that research has yet to discover the prevalence of reinstatement in common treatment settings.

Spontaneous Recovery

Spontaneous recovery differs from other forms of relapse in that there may be no changes in context, in the immediate response to severe challenging behavior, or the contingencies in place for alternative behavior, yet the previously extinguished severe challenging behavior temporarily reoccurs (Bouton, 1993; Lerman et al., 1999). When there is a period of time in which the individual is not contacting opportunities that, prior to extinction procedures, previously evoked the severe challenging behavior, the reintroduction of these opportunities may incur the severe challenging behavior again. These opportunities for spontaneous recovery may come in the form of breaks from treatment over holidays, weekends, vacations, and so on. Any time there is a break in and a reintroduction to treatment, there is an opportunity for spontaneous recovery to occur. Similar to reinstatement, researchers have not yet determined the prevalence of spontaneous recovery in clinical practice.

Repercussions of Relapse

These various forms of relapse can have several repercussions that may negatively affect the individual and their caregivers. When an individual’s severe challenging behavior is high-frequency and high-intensity, the repercussions can be very impactful. For example, relapse of elopement in the form of bolting or pica in the form of consuming toxic substances could result in serious and long-lasting consequences, such as being hit by a vehicle or death from poisoning. Given that the everyday practitioner may not operate in a facility or at a service level that allows for the safe and effective assessment and treatment of these high-intensity severe challenging behaviors, it is important to consider the repercussions of relapse of any form or intensity of severe challenging behavior.

Although the relapse of relatively less intense severe challenging behavior (e.g., mild aggression or SIB) may pose as immediate health- or safety risks, relapse of any type of severe challenging behavior can have negative impacts on the individual’s treatment outcomes and service delivery. In circumstances of relapse, behavior technicians or caregivers may have a higher likelihood of committing treatment integrity errors that can be detrimental to treatment progress (Mitteer et al., 2018; Williams et al., 2023). For example, if severe challenging behavior relapses in the form of resurgence during reinforcement schedule thinning following FCT, a behavior technician may inadvertently deliver reinforcement for severe challenging behavior that cooccurs with the functional communication response (FCR). If severe challenging behavior relapses in the form of renewal when a treatment team transitions a successful treatment from a center-based setting to the home setting and a practitioner did not proactively prepare the technicians and caregivers for the possibility of relapse, the treatment team may encounter safety risks (e.g., if the home setting was not properly modified for safety prior to the transition) and the practitioner may face possible technician burnout or turnover and reduced buy-in from caregivers (Brown, 2021; Cymbal et al., 2022; Plantiveau et al., 2018).

Another scenario in which practitioners might experience repercussions of relapse is when clients meet their treatment goals and transition out of services. Often, objective goals for rates of severe challenging behavior include an 80–90% reduction from baseline (Greer et al., 2016), which means that, in many cases, severe challenging behavior can still be occurring at a low rate upon discharge or transition of services, providing an opportunity for treatment deterioration. Even if caregivers received training on the BIP, the low rate of severe challenging behavior that may remain after discharge increases the risk that the caregiver will make integrity errors (Mitteer et al., 2018) or others in the environment who are unfamiliar with the BIP will deliver reinforcement for severe challenging behavior. There may also be situations in which a caregiver must deliver reinforcement for severe challenging behavior that recurs in an environment in which it may be unsafe or impractical to adhere to components of a BIP (e.g., extinction for severe challenging behavior). For example, if an adolescent engages in severe aggression toward a bystander in the grocery store, a caregiver may be obligated to deliver the functional reinforcer to decrease the possibility of harm and avoid escalation of the situation (e.g., involvement of law enforcement). Given the prevalence of relapse (Briggs et al., 2018; Falligant et al., 2022; Haney et al., 2022; Muething et al., 2021), the likelihood of caregivers encountering situations such as those described above, and the negative impact of integrity errors on treatment maintenance (St. Peter Pipkin et al., 2010), it is reasonable to state that a large repercussion of relapse of severe challenging behavior is treatment deterioration that may occur post-discharge from treatment services. By being aware of these possible and serious repercussions of relapse, practitioners may be more inclined to react rapidly and cautiously when they observe relapse with their clients.

Individual Client Considerations

In addition to being aware of the possible repercussions of relapse, practitioners should ensure they are familiar with each client, their preferences, unique characteristics, and circumstances that may contribute to the possibility of relapse. We recommend the following considerations specifically when it comes to clients who engage in severe challenging behavior.

First, practitioners should be aware of referral concerns by ensuring that they ask specific questions about current and past instances of severe challenging behavior. Practitioners should gather information about the different topographies of severe challenging behavior, the associated frequency, intensity, and outcomes of each topography (e.g., see The Destructive Behavior Severity Scale in Fisher et al., 2013), and information from caregivers on how they have managed and responded to severe challenging behavior in the past. Gathering this detailed information on severe challenging behavior will not only help the practitioner prepare for the safe and effective delivery of services (e.g., staffing ratios and experience, protective padding, caregiver collaboration), but may prepare them to anticipate and mitigate the possible relapse of that severe challenging behavior during and following treatment. In addition to referral concerns, practitioners should familiarize themselves with the client’s medical history and any ongoing medical concerns. When a client presents with severe challenging behavior, it is important to consider the possible impact that medications and underlying medical conditions might have on the current and future occurrence of severe challenging behavior (Copeland & Buch, 2019). By collaborating with medical providers, practitioners will be better prepared to rule in or rule out the possibility that the return of severe challenging behavior is due to one of the various relapse types outlined above (e.g., renewal and resurgence) as opposed to co-occurring medical conditions, changes in medication, or other setting events (Kennedy & Meyer, 1996). For example, if a practitioner conducts an intake for a client with severe challenging behavior concerns in the springtime, establishes an effective treatment for the severe challenging behavior by summertime, and the severe challenging behavior recurs in the fall, it is possible that seasonal allergies could have impacted the establishing operation(s) for and recurrence of severe challenging behavior. By becoming informed of and tracking the client’s medication regimens and underlying medical conditions, practitioners can potentially avoid confusing the recurrence of severe challenging behavior due to these variables for operant relapse triggered by a change in context or reinforcement contingency.

Practitioners need to also be aware of unique family considerations that may impact their ability or willingness to implement severe challenging behavior treatment protocols. By asking questions and being aware of cultural, religious, and socioeconomic considerations (Fong et al., 2016), practitioners will be better prepared to select and modify a treatment package that the caregivers will adhere to, thus decreasing the chances of relapse that may occur due to treatment integrity errors or non-adherence. For example, if a practitioner knows that a family does not have access to, or the resources for, expensive equipment (e.g., protective padding) or reinforcers (e.g., tablet, high frequency edible reinforcement) that a treatment team uses in a treatment package, they will be prepared to coordinate with an interdisciplinary team to help the family get access to those resources or use equipment and reinforcers consistent with what the family already has access to. This type of close collaboration with a client’s caregivers and other interdisciplinary team members (e.g., speech therapist, physical therapist) will equip the practitioner with awareness of the preferences and feasibility of treatment recommendations they provide, thereby better mitigating the possibility of future relapse that could occur following a caregiver’s inability to implement recommended procedures.

Next, practitioners should ensure that they conduct a functional behavior assessment (FBA) such that they are aware of the function of the severe challenging behavior (Betz & Fisher, 2011). Without a clear understanding of the function(s) of the behavior, practitioners may be more likely to implement a non-function-based treatment and encounter more difficulties in responding appropriately to the possible later relapse of that behavior. For example, consider a client that presents with severe head banging. If a practitioner moves straight to treatment by teaching a single FCR for social attention, access to preferred tangible items, and escape from academic demands (e.g., Ghaemmaghami et al., 2016) and then head banging recurs later in treatment, it will likely be more difficult for the practitioner to tease out which establishing operation (single or combined) may be impacting relapse most significantly, making it difficult to determine how to best respond and modify the treatment package. Thus, practitioners who have strong evidence concerning the precise function(s) of behavior may be more prepared to manage relapse should it occur.

Finally, practitioners should be aware of how each client responds to changes. Changes to pay close attention to include changes in the physical environment (e.g., new therapy room), staffing (e.g., when a team member calls out sick), and reinforcement availability, magnitude, and frequency (e.g., their preferred tablet runs out of battery, a reinforcement schedule is thinned). Making and analyzing specific modifications to the treatment package in Phase 3 of the three-phase arrangement will assist practitioners in identifying to what extent and under what conditions the treatment package will continue to be effective. Collecting detailed data in a way that allows a practitioner to analyze changes in severe challenging behavior that may occur may help the practitioner monitor and better prepare for the possibility of future relapse.

Data Collection and Ongoing Data Review

Further considerations for practitioners to be cognizant of regarding relapse are establishing routine practices of monitoring the reliability of the data that the treatment team collects by building in consistent data reliability measures (i.e., interobserver agreement data), and monitoring treatment integrity (Vollmer et al., 2008). Decisions regarding the treatment package should be data-based. Thus, it is crucial to review the reliability of the data on an ongoing basis to determine if any variability or changing trends are a result of the client’s behavior or are a result of inaccurate or inconsistent data collection. For example, the data may appear to indicate that severe challenging behavior has relapsed, but the change in the data is actually a false negative treatment outcome stemming from inaccurate data collection. Consistent checks for interobserver agreement may prevent the practitioner from mistakenly attributing the change in data to operant relapse. Just as reliability measures verify the data collected, treatment integrity checks confirm the accuracy of the treatment implementation, treatment integrity checks provide a means to determine whether the intervention is implemented as outlined by staff, caregivers, or other stakeholders. More specifically, treatment integrity checks may provide a means for identifying procedural drift that could later result in relapse. In addition to establishing data reliability and treatment integrity measures, reviewing the data on a regular basis is necessary to better detect relapse of severe challenging behavior as it occurs. To more effectively evaluate the data, practitioners may consider more detailed data collection such as session-by-session data (e.g., time-based sessions) rather than depicting data based on daily or weekly responding. Breaking down bigger data-collection intervals into smaller portions will assist in identifying any adverse trends as they emerge rather than once they become a more prominent problem. Of course, increasing the number of data points available will only be beneficial to the practitioner if they analyze the data regularly. Ideally, the practitioner would examine the data multiple times per day, depending on the length of their clients’ appointments.

Reacting to Relapse After it Happens

Once a practitioner has created opportunities to be aware of relapse, they must now be prepared to use this information and react when it occurs. The clinical decisions that follow may depend on why the behavior has recurred in the first place. That is, it may be helpful to determine which relapse type(s) have contributed to the severe challenging behavior’s return. Reviewing the conditions that preceded the reemergence of severe challenging behavior may assist with identifying the form of relapse that occurred, which may allow practitioners to make a more informed decision regarding the reaction to relapse. Recent evidence suggests that the presence of one form of relapse is not indicative of multiple forms (see Muething et al., 2024). Thus, approaching each type of relapse with specific strategies appears warranted. This approach is similar to that of functional assessment and function-based treatment. As a standard practice, behavior analysts identify the function of a severe challenging behavior so that a function-based, effective treatment can be implemented (e.g., Beavers et al., 2013; Greer et al., 2016). Identifying the relapse arrangements that have contributed to the recurrence may inform the most effective course of action to immediately remedy and potentially mitigate future instances of severe challenging behavior.

An effective reaction to relapse could be defined as one that increases the likelihood of safely and quickly reestablishing clinically desirable (e.g., 80% decrease from baseline levels) and socially acceptable low levels of severe challenging behavior. Effective reactions to relapse may also include procedures aimed at introducing an immediate abolishing operation for severe challenging behavior (Langthorne & McGill, 2009), such that the treatment team may have sufficient time to develop a more extensive plan for reducing the relapsed severe challenging behavior or adding mitigation procedures to the intervention plan. Practitioners should also recognize that most of the reactions to relapse that we offer for consideration are only meant to be temporary changes to the BIP. We acknowledge that clients may make significant progress with treatments before relapse occurs. As a result, practitioners may wish to both quickly eliminate the relapsed severe challenging behavior and maintain the progress that has already been made within their current plan.

Notably, we contend that an effective reaction to relapse differs from relapse-mitigation procedures. While relapse mitigation procedures are intended to proactively decrease the future likelihood or magnitude of relapse (see Kimball et al., 2023), an effective reaction to relapse is instead an approach to managing relapse once it has already happened. A burgeoning body of literature exists on potential strategies to reduce the detrimental impact of relapse through mitigation procedures (e.g., Fuhrman et al., 2016; Haney et al., 2021), but the optimal methods for regaining robust treatment effects in the aftermath of relapse is an underexplored area of research. Despite the paucity of research intentionally focused on reacting to relapse when it occurs, our hope is to at least equip practitioners with some options to consider until this gap in the literature is filled. Practitioners should therefore interpret our options to consider for reacting to relapse cautiously because, to our knowledge, few studies, if any, have specifically evaluated targeted strategies to regain treatment effects once relapse has already transpired. This may be due, in part, to the fact that such research would necessitate either very patient opportunistic research or intentionally occasioning relapse, the latter of which may introduce several unpalatable risks. Nevertheless, we believe that the bodies of literature concerning the causes of relapse and the treatment of severe challenging behavior have advanced far enough that behavior analysts can begin to extrapolate potential effective and conceptually-sound reactions to relapse from those respective areas of study.

Our options to consider for effective reactions to relapse are influenced by four general factors. First, some options are based on the known causes of various types of relapse. That is, each type of relapse occurs because of different changes in the environment; thus, it might be valuable for practitioners to react to each type of relapse in a way that relates to that specific change in the environment (Kimball et al., 2023; Muething et al., 2024). For example, because resurgence occurs due to challenges to reinforcement for the alternative response (e.g., FCRs), effective reactions to resurgence might involve restoring environmental conditions that favor reinforcement for the alternative response. To further illustrate this point, consider that applied research has demonstrated that treatment integrity with DRA does affect resurgence, but not renewal (Kelley et al., 2018; Saini et al., 2018; Volkert et al., 2009). Second, some of our options to consider for reacting to relapse slightly overlap with existing recommendations for relapse mitigation procedures in the published literature (e.g., function-based noncontingent reinforcement; Marstellar & St. Peter, 2014). Third, many of our options to consider for reacting to relapse stem from practice guidelines on treating high-intensity severe challenging behavior (Berg et al., 2016; Briggs & Greer, 2021; Geiger et al., 2010; Hagopian et al., 2013; Hausman et al., 2021; Lindgren et al., 2020; Phillips et al., 2017; Slocum & Call, 2021). Lastly, some themes of our options for consideration are founded in the conceptual underpinnings and predictions of various quantitative theories and a narrative account of relapse such as Behavioral Momentum Theory, Resurgence as Choice, and Context Theory (Bouton, 1993; Shahan & Craig, 2017; Shahan & Sweeney, 2011). Complete descriptions of those frameworks are beyond the scope of the current paper, but we direct readers to Greer and Shahan (2019) and Kimball et al. (2023), who recently provided thorough summaries. Using these general factors, we compiled a collection of options for practitioners to consider when reacting to relapse that may result in efficient and effective solutions. What follows is a detailed description of the various options to consider for each type of relapse.

Options to Consider When Reacting to Relapse

Figure 1 depicts options that practitioners may consider when deciding on reactive approaches for relapsed challenging behavior. But before outlining reactive options to consider when relapse occurs, including some options that may change aspects of the behavior intervention plan, it is vital to underscore that practitioners may consider temporarily persisting with the current behavior intervention plan instead of immediately making changes. Although it may be tempting to make rapid and significant changes to the BIP to suppress challenging behavior, that may not always be necessary. Applied researchers have documented that some instances of relapse (e.g., renewal and resurgence) are short-lived (cf. Oliver from Greer et al., 2019) and subside within a few clinical sessions (e.g., Muething et al., 2020, 2021). Therefore, the first option that practitioners might consider when reacting to relapse is briefly continuing with the behavior intervention plan as it is currently written to see if relapsed behavior decreases to pre-relapse levels without making changes to the plan. However, practitioners should not sacrifice client, staff, or stakeholder safety when considering this first option. Said another way, practitioners should not avoid making changes to the behavior intervention plan when relapse occurs if those changes increase the immediate safety of clients, staff, or stakeholders.

Fig. 1.

Reacting to Relapse Considerations

If rates of relapsed behavior do not decrease after temporarily persisting with the current behavior intervention plan, the next step in considering an effective reaction to relapse is to check for any recent, objective and detectable environmental changes that could be hypothesized to trigger the relapse of severe challenging behavior. We propose that practitioners should contemplate the following environmental changes as potential sources of relapse: a) inadvertent delivery of reinforcer(s) for severe challenging behavior when the intervention includes extinction (i.e., a commission error), b) programmed or unprogrammed context changes such as a shift in the treatment implementer or setting, and c) programmed or unprogrammed changes to the reinforcement conditions for the alternative response. If none of these general classes of environmental changes are immediately evident, practitioners should examine treatment session logs and graphs of treatment data to look for discernible changes in the environment. In addition, it would be prudent to interview all relevant staff and stakeholders such as caregivers, teachers, and interdisciplinary team members, if applicable. Such actions may be useful for gathering all relevant information that might point practitioners in the right direction for hypothesizing the environmental change(s) that caused relapse.

Spontaneous Recovery

If a practitioner has exhausted all possible sources of information, and still cannot identify objective environmental changes that could be hypothesized to cause relapse, there is a chance that spontaneous recovery has occurred. After spontaneous recovery has occurred, practitioners can take some steps to bolster their ability to swiftly identify further instances of spontaneous recovery in the future and identify environmental changes that could spur other forms of severe challenging behavior. First, practitioners should think about collecting treatment integrity data more frequently for staff and caregiver implementation of the BIP (Vollmer et al., 2008). Observing high levels of treatment integrity with BIP implementation across treatment implementers may increase one’s confidence that resurgence and reinstatement haven’t occurred. For example, if the practitioner has data demonstrating that treatment implementers are not making errors of omission in the form of withholding reinforcement for FCRs or errors of commission in the form of accidentally reinforcing severe challenging behavior, the search process for identifying environmental changes that could trigger relapse will be more efficient. Additionally, practitioners should consider teaching and requiring staff to submit more detailed session notes specifically concerning client severe challenging behavior and the BIP. In the enhanced session notes, staff should include information about common environmental changes that could trigger relapse (e.g., the BIP was implemented in a novel setting, the staff couldn’t feasibly provide the reinforcer for appropriate behavior in a rapid fashion, etc.) or unique anecdotes about the client’s behaviors related to the implementation of the BIP. Practitioners can use an assortment of interventions to improve the objectivity and overall completion of staff session note writing such as checklists, performance feedback, and didactic presentations (Brown et al., 2021a, b, c; Luna & Rapp, 2019; Piazza et al., 2021). Finally, practitioners should establish more frequent and thorough communication (e.g., phone calls, emails, etc.) between stakeholders and the treatment team to help with relapse detection and management. Effective detection of and responses to relapse may depend on the speed of the response. Thus, it would behoove practitioners to train stakeholders to swiftly communicate if significant environmental changes or relapse have occurred.

Reinstatement

In the case of reinstatement, it is paramount that all staff and stakeholders attempt to resume high levels of treatment integrity with extinction and differential reinforcement of FCRs (and other desirable behaviors) as soon as possible. Practitioners could also take this opportunity to conduct booster staff and stakeholder training with the BIP until all treatment implementers consistently demonstrate high levels of treatment integrity with all components of the BIP. For example, practitioners might use task clarification (Choi & Johnson, 2022) and behavioral skills training (BST; Parsons et al., 2012) to straighten out any confusion with how to implement the BIP, provide models of correct implementation, and give practice opportunities for rehearsing implementation of the BIP. Following booster training, it would also be advantageous to continue collecting frequent treatment integrity data for staff and stakeholders, specifically on the use of the extinction component.

Furthermore, given that reinstatement has occurred because a treatment implementer accidentally reinforced severe challenging behavior, practitioners could consider taking steps to ensure that the environment heavily favors the emission and reinforcement of FCRs and other socially desirable behaviors. Recent histories of reinforcement may strongly influence the allocation of behavior to the relapsed severe challenging behavior instead of FCRs; thus, practitioners may consider using prompting strategies and the manipulation of reinforcement parameters to support the reliable occurrence of FCRs (Greer & Shahan, 2019). For instance, to increase the likelihood that FCRs will occur instead of relapsed severe challenging behavior, practitioners could consider reintroducing a more intrusive prompt for the FCR and accepting a less effortful FCR topography. These options for consideration are empirically supported by applied research on FCT and the treatment of severe challenging behavior (e.g., Buckley & Newchok, 2005; Cagliani et al., 2019; Horner & Day, 1991; Randall et al., 2021; Richman et al., 2001; Romani et al., 2013; Shirley et al., 1997). Consider a situation in which the client had progressed to a point in treatment when staff no longer needed to provide prompts for FCRs during the presence of the relative establishing operations (EO) and the client reliably used vocal FCRs (e.g., “may I have my toy back?”) independently. In a case such as this, immediately following relapse, the practitioner may consider temporarily requiring and reinforcing a less complex vocal response such as “toy please” or a less effortful FCR topography such as a card exchange or card touch (DeRosa et al., 2015; Houck et al., 2022) while also using a 0 s (s) prompt delay during all exposures to the relevant EO. By returning to a more intrusive, controlling prompt (i.e., prompt which reliably evokes the appropriate response; e.g., Fisher et al., 2007) when severe challenging behavior recurs, practitioners can quickly ensure that appropriate behavior contacts reinforcement, which may increase the likelihood that the appropriate behavior will continue to be emitted, rendering the severe challenging behavior unnecessary.

However, one potential risk of returning to a more intrusive, controlling prompt is the chaining of appropriate behavior and severe challenging behavior. That is, it is possible that immediately prompting an appropriate behavior following the relapse of severe challenging behavior may reinforce both of those behaviors, leading to the appropriate and severe challenging behaviors being “chained together,” or co-occurring in the future (cf. Landa et al., 2022). Whenever possible, practitioners should contemplate implementing the prompting strategy outlined above in conjunction with a changeover delay (COD; Brownstein & Pliskoff, 1968) to prevent chaining. In a COD, a certain amount of time must pass before a learner receives reinforcement after changing from one behavior to another; for example, from a target severe challenging behavior to a more appropriate alternative (e.g., Brown et al., 2021a, b, c; Fuhrman et al., 2016; Simmons et al., 2022). Through the use of systematic prompting, prompt fading (e.g., progressive time delay), and COD procedures, practitioners may be able to quickly regain a socially significant result of reduced severe challenging behavior and independent appropriate behavior, and prevent the chaining of severe challenging behavior and appropriate behavior together.

Next, to help sway the allocation of behavior away from the relapsed severe challenging behavior and toward FCRs, practitioners might ponder temporarily manipulating FCR reinforcement parameters such as rate (i.e., the schedule of reinforcement), magnitude, quality, and immediacy. In short, practitioners can leverage reinforcement parameters to create a recent history of reinforcement for FCRs that may outweigh the recent history of reinforcement created by the commission errors that reinforced severe challenging behavior (Greer & Shahan, 2019). This general approach to manipulating reinforcement parameters to favor FCRs stems from the matching law (Fisher et al., 2022; Herrnstein, 1961; Reed & Kaplan, 2011), and the approach is empirically support by basic, translational, and applied research (e.g., Athens & Vollmer, 2010; Borrero et al., 2010; Briggs et al., 2019; Peterson et al., 2009; Piazza et al., 1997; Weinsztok & DeLeon, 2022). For example, if the BIP currently prescribes an intermittent schedule of reinforcement for FCRs through incorporating delays or denials (e.g., Ghaemmaghami et al., 2016), a temporary return to a continuous schedule of reinforcement (i.e., fixed ratio [FR] 1) for FCRs may be in order. Alternatively, if a practitioner uses FCT with a multiple schedule to accomplish reinforcement schedule thinning and teach discrimination of reinforcer availability, one could return to a schedule thinning step in which the S^Δ interval is significantly shorter (Greer et al., 2016) and the S^D interval is longer. Beyond the schedule of reinforcement for FCRs, practitioners could also substantially increase the magnitude and quality of reinforcement for FCRs. Imagine a situation in which a client has experienced considerable success with the BIP for severe challenging behavior, and FCRs now only produce small magnitudes of reinforcement, such as 2 min. of attention from caregivers. Once reinstatement occurs, the practitioner could consider temporarily increasing the reinforcement magnitude for FCRs from 2 min. to 5 min. of attention from caregivers and increase the reinforcement interval's quality by adding access to highly preferred tangible items. Again, while researchers haven’t expressly tested the impact of manipulating reinforcement parameters as reactions to reinstatement, applied researchers have used these strategies to sway the allocation of behavior from severe challenging behavior to socially desirable behaviors (e.g., Athens & Vollmer, 2010; Briggs et al., 2019).

Lastly, if reinstatement has occurred because a stakeholder reinforced severe challenging behavior, practitioners consider reevaluating the long-term feasibility of stakeholders implementing extinction. The occurrence of reinstatement may be the right opportunity for practitioners to revisit the conversation with stakeholders concerning their ability to consistently implement extinction. While engaging in such a conversation, the practitioner should patiently acknowledge the stakeholder’s opinions regarding the challenges that come with implementing extinction and respond to those opinions without judgement (Taylor et al., 2019). Furthermore, practitioners should also consider some of the risks associated with the use of extinction at all. For example, severe challenging behavior treated with extinction must occur in a location that is safe; one that allows preparation of the physical space, such as use of padded surfaces and personal protective equipment. If caregivers share that they do not think that they will be able to continue with a BIP based on extinction, practitioners should consider the burgeoning volume of literature on function-based treatments without extinction, and offer the caregivers intervention options that do not require extinction components (Brown et al., 2021a, b, c; Trump et al., 2020; Vollmer et al., 2020).

Renewal

If the practitioner believes the relapse of severe challenging behavior is renewal, they should next determine if the context change was programmed or unprogrammed because our options to consider for reacting to renewal are slightly different for each circumstance.

Programmed Context Change During Generalization Training

Research suggests that practitioners should actively program and test for generalization of behavior change (Ghaemmaghami et al., 2021; Neely et al., 2018; Stokes & Baer, 1977; Stokes & Osnes, 1989). Testing for generalization often entails deliberately implementing the treatment with novel implementers or in novel settings to measure for sustained behavior change across various stimulus conditions that the client might encounter post-treatment (e.g., Fisher et al., 2015). Similarly, after achieving successful treatment outcomes with trained behavior technicians in a clinical setting, the practitioner might wish to test for generalization by having familiar stakeholders implement the intervention in the natural environment while trained behavior technicians provide support (Greer et al., 2019; Saini et al., 2018). In each of these scenarios, the practitioner is introducing programmed context changes, and recent research suggests that we should potentially expect renewal to occur (Falligant et al., 2021; Mitteer et al., 2022). If renewal occurs during a programmed context change and trained behavior technicians are present, practitioners could consider persisting with the prescribed procedures from the current BIP, remaining in the generalization context if possible, and maintain everyone’s safety. If trained behavior technicians are either present to implement treatment or provide coaching and support to the stakeholder implementing treatment, the likelihood of treatment integrity errors occurring may be lower (Artman-Meeker et al., 2017; Bethune & Ayers, 2020), and practitioners can promote the persistence of treatment implementation in the generalization context (cf. Suess et al., 2014). Alternatively, if a trained behavior technician is not the treatment implementer during the context change or trained staff are not available to provide support to the stakeholder implementing treatment, practitioners could considerreturning to the typical treatment context, especially when severe challenging behavior is unmanageable.

In a study on renewal prevalence, Muething et al. (2020) found that the magnitude of renewal gradually decreased with each treatment session following the context change, and pre-context change levels of severe challenging behavior were achieved within five treatment sessions on average. Those data imply that the increases in severe challenging behavior due to renewal often quickly subside within a short period of time. However, that brief window of time when severe challenging behavior has renewed also provides ample opportunity for treatment implementers to accidentally reinforce the relapsed behavior (i.e., treatment integrity error of commission), which may worsen the magnitude of relapse. Practitioners should be aware of this possibility, which is supported by translational research with socially significant populations (Mitteer et al., 2021). To that end, practitioners may consider prioritizing the fidelity of extinction procedures when renewal occurs during programmed context changes.

Unprogrammed Context Change

When renewal occurs during unprogrammed context changes, ideally, practitioners should also promote adherence to the prescribed procedures from the BIP. Nevertheless, we realize that these conditions might not always include highly trained staff who can implement the treatment with optimal treatment integrity or provide support to those who are implementing the treatment. Accordingly, we offer three general approaches to consider for reacting to renewal during unprogrammed context changes.. First, similar to one of our options to consider for reacting to reinstatement, practitioners could introduce a temporary increase in the density, magnitude, quality, and immediacy of reinforcement for FCRs. For example, consider a learner who has escape-maintained severe challenging behavior and FCRs are intermittently reinforced with 30 s breaks from the aversive task and they get to select one highly preferred tangible item to play with during the break. If renewal occurs during an unprogrammed context change for this learner, the practitioner could temporarily revert back to continuously reinforcing FCRs, but with 2 min breaks with access to behavior technician attention and several highly-preferred tangible items. In this way, the practitioner has modified FCR reinforcement parameters to strongly favor the emission of FCRs instead of the renewed severe challenging behavior, and this recommendation is generally supported by the predictions of the matching law and applied research on the treatment of severe challenging behavior (e.g., Baum, 1974; Borrero et al., 2010; Greer & Shahan, 2019; Peck Peterson et al., 2005; Rogalski et al., 2020). Second, practitioners could consider further influencing the probability of observing FCRs instead of renewed severe challenging behavior by temporarily requiring and reinforcing a less effortful or complex FCR topography (e.g., vocal response versus card exchange) and regressing to immediately prompting FCRs when the relevant EO is present. These options for consideration are empirically supported by applied research on FCT and treating severe challenging behavior (e.g., Buckley & Newchok, 2005; Cagliani et al., 2019; Horner & Day, 1991; O’Neill et al., 2014; Randall et al., 2021; Richman et al., 2001; Romani et al., 2013; Shirley et al., 1997). Third, even if the BIP is based on differential reinforcement of the FCR (i.e., DRA), practitioners might considertemporarily using very dense or continuous NCR plus extinction until it is possible to return to the typical treatment context. This third option for consideration aims to reduce exposure to the relevant EO that evokes severe challenging behavior (and FCRs), thereby reducing the likelihood that the renewed severe challenging behavior will worsen. Although some basic and translational research has demonstrated that renewal can occur despite schedules of NCR (e.g., Finch et al., 2022; Nakajima et al., 2002), very dense or continuous NCR may completely eliminate exposure to the EO that evokes severe challenging behavior resulting in overall less severe challenging behavior, which can promote the safety of everyone involved. Applied research on the treatment of severe challenging behavior supports this as a potential option (e.g., Fritz et al., 2017; Kahng et al., 2000).

Resurgence

The implications of resurgence occurring due to purposeful, programmed changes (e.g., thinning the density of the reinforcement schedule) as compared to resurgence occurring due to a treatment integrity error of omission are vastly different, therefore, practitioners may consider reacting to resurgence differently based on whether the worsening reinforcement conditions for the alternative response were a) purposefully programmed or b) a consequence of a treatment integrity error of omission.

Programmed Change to Reinforcement Conditions for Alternative Response

Our first option to consider for reacting to resurgence stemming from a programmed change to reinforcement conditions for the alternative response is to potentially regressing to a previous iteration of the BIP that a) included more favorable reinforcement conditions for the alternative response, and b) was associated with low to zero levels of severe challenging behavior. Applied research on FCT and the treatment of severe challenging behavior support this approach (e.g., Hagopian et al., 2005, 2011; Kranak & Brown, 2024). For example, if resurgence occurred after the practitioner reduced the magnitude of reinforcement for the FCR from 2 min. to 1 min., returning to the 2 min. reinforcement interval may effectively reduce relapsed severe challenging behavior back to desirably low levels. Similarly, if resurgence immediately ensued after increasing the academic response requirements (e.g., completing math problems) from an FR 5 schedule of reinforcement to an FR 10 during the treatment of severe challenging behavior maintained by escape from academic instructions, the practitioner might temporarily revert back to the FR 5 schedule to reduce the alternative response effort (e.g., Davis et al., 2018). As another example, if a practitioner observes resurgence during reinforcement schedule thinning when progressing to a more intermittent schedule for the FCR, they could contemplate returning to a more continuous schedule of reinforcement (i.e., a denser schedule; Hagopian et al., 2011). As an illustration of regressing to a denser schedule of reinforcement for the FCR, if one is using delay and denial tolerance training (e.g., Hanley et al., 2014) and resurgence occurred after the proportion of FCRs immediately reinforced was decreased, one could consider returning to a schedule in which a larger proportion of FCRs are immediately reinforced. If one is instead using a stimulus control procedure to accomplish reinforcement schedule thinning during FCT, such as a multiple schedule intervention (e.g., Betz et al., 2013), one could consider returning to a previous schedule thinning step following resurgence that included a shorter S^Δ duration and a longer S^D duration thereby reducing the amount of time that reinforcement for FCRs is unavailable (Hagopian et al., 2004; Kranak & Falligant, 2022).

If practitioners frequently observe resurgence during reinforcement schedule thinning with FCT and multiple schedule training, which often necessitates returning to a denser schedule of reinforcement for the FCR, adding an NCR component to the BIP could be beneficial. For example, if severe challenging behavior is maintained by social positive reinforcement such as access to adult attention, and the S^Δ of the multiple schedule involves extinction for FCRs and severe challenging behavior while the learner waits for a set amount of time without access to attention, practitioners could consider noncontingently providing access to competing stimuli such as preferred tangible items during the S^Δ interval temporarily. Although researchers have not specifically tested this approach for reacting to resurgence, applied researchers have found this approach effective during FCT with multiple schedules when increasing the S^Δ interval to relatively extended durations (e.g., Fuhrman et al., 2018; Hagopian et al., 2005; Simmons et al., 2022).

If severe challenging behavior resurged while intentionally shaping progressively more complex FCR topographies (e.g., Ghaemmaghami et al., 2018; Santiago et al., 2016), practitioners could consider temporarily returning to requiring a less complex FCR. For instance, if severe challenging behavior is maintained by social positive reinforcement in the form of access to tangible items, and a practitioner just changed the FCR response requirement from “toy please” to “may I have my toy please,” the practitioner might return to only requiring “toy please” if low levels of severe challenging behavior were previously observed when only that FCR topography was required for the delivery of reinforcement. Similarly, if one observes resurgence after transitioning from requiring a card exchange FCR to a vocal response (e.g., Randall et al., 2021), it could be helpful to temporarily only require a card exchange FCR because that FCR topography could be less effortful for some learners. This option for consideration is supported by applied research on FCT and the treatment of severe challenging behavior (e.g., Buckley & Newchok, 2005; Cagliani et al., 2019; Horner & Day, 1991; Richman et al., 2001). Moreover, much like the option of returning to a more intrusive prompt for the FCR following the occurrence of reinstatement, practitioners could also consider returning to a more intrusive prompt for the FCR after observing resurgence during reinforcement schedule thinning or when shaping increasingly complex FCRs. Applied research on FCT and the treatment of severe challenging behavior provide empirical support for this option (e.g., Romani et al., 2013; Shirley et al., 1997).

Treatment Integrity Error of Omission

If the practitioner is present when a treatment implementer (e.g., behavior technician, teaching assistant, or caregiver) engages in an omission error resulting in resurgence, the practitioner could contemplate conducting booster BIP training sessions with that individual as soon as possible until they consistently implement the BIP with perfect treatment integrity. This option to consider is supported by applied research on training stakeholders to implement BIPs (e.g., Nuta et al., 2021). The booster training on the BIP should likely include the critical parts of behavioral skills training such as verbal and written instructions, rationale, modeling, rehearsal, and performance feedback (Parsons et al., 2012). What’s more, to increase the efficiency of retraining treatment implementers following resurgence, practitioners could consider exclusively retraining on the specific BIP component that wasn’t implemented accurately instead of completely retraining the entire BIP (Cook et al., 2015).

Suppose the practitioner was not present to objectively observe the omission error or a treatment implementer does not immediately report to the practitioner that they accidentally engaged in a treatment integrity omission error that resulted in a resurgence of severe challenging behavior. In that case, a potential first step in effectively reacting to resurgence following an error of omission is to attempt to trace back who engaged in the treatment integrity error that resulted in resurgence and identify the type of omission error so that practitioners can conduct targeted stakeholder or staff training. This process could be accomplished by interviewing staff and stakeholders and closely examining recent session notes or communication logs. For instance, if a practitioner traces the source of resurgence to a primary caregiver who shared that they are simply having difficulty reinforcing FCRs quickly enough (i.e., before the learner reverts back to engaging in severe challenging behavior), the practitioner could then specifically emphasize the importance of reinforcer immediacy during caregiver retraining instead of covering the entirety of the BIP. If a practitioner traces the source of resurgence to a primary caregiver, the practitioner should avoid passing judgement about the treatment integrity error. Caregivers may perceive this conversation about the treatment integrity error as the practitioner blaming them for the severe challenging behavior relapse. In an effort to provide compassionate care, practitioners should focus the problem-solving conversation on solutions and recognize the caregiver’s skills and past efforts with implementing the BIP (Taylor et al., 2019). For a different learner who engages in card exchanges as their FCR topography, a practitioner might trace the source of resurgence to a backup behavior technician who recently forgot to craft additional FCR cards for a client who often loses their FCR cards. In this case, the practitioner might forgo further training on the BIP entirely for this staff and instead provide additional supports that increase the likelihood that the treatment team has the time and resources to craft more FCR cards when they are lost. This option of selecting different performance management strategies based on the source of low treatment integrity is supported by applied research on performance diagnostics (e.g., Carr et al., 2013). We acknowledge that merely interviewing staff and stakeholders may not always reliably identify the treatment implementer who exhibited the treatment integrity error or help to pinpoint the type of omission error, but it is still possible that these conversations will help increase the efficiency of retraining proper implementation of the BIP (Hodges et al., 2020).

After retraining treatment implementers, practitioners might also consider establishing a system for more frequent data collection on treatment integrity with the BIP (Vollmer et al., 2008). Frequent data collection on treatment integrity may help the practitioner identify and solve problems with everyone’s implementation of the BIP before more errors result in further resurgence. If treatment integrity data suggest that stakeholders such as teachers or caregivers cannot consistently implement the prescribed BIP with high treatment integrity, the practitioner may consider reducing the complexity of the BIP such that implementers will have fewer BIP steps to complete (DiGennaro Reed et al., 2014; Robertson et al., 2020; Zimmerman et al., 2022), thereby potentially reducing the likelihood of omission errors that could result in resurgence. Should the practitioner deem that all of the prescribed components of the BIP are critically necessary to maintain socially significant decreases in severe challenging behavior, they might consider using the Performance Diagnostic Checklist-Parent (PDC-P; Hodges et al., 2020) to identify sources of low treatment integrity. The PDC-P is an interview tool that practitioners may use to identify sources of low treatment integrity beyond a lack of complete training and BIP complexity, such as performance consequences, response competition, or lack of resources. The important message here is that practitioners can use frequent data collection on stakeholder treatment integrity and increased stakeholder communication to arrive at a version of the BIP that produces meaningful decreases in severe challenging behavior and can be implemented with integrity consistently.

Limitations to Response Planning

Given the dynamic nature of the environment in treatment and non-treatment settings, practitioners might not always be able to definitively conclude the specific environmental change(s) that contributed to relapse, as the cause of relapse may be multifaceted (Mitteer et al., 2022; Wathen & Podlesnik, 2018). For example, when providing comprehensive treatment services funded by third-party payers, case supervision is often provided to behavior technicians by supervising, masters-level practitioners within a certain number of hours per month. That is, it may be impractical for the behavior analyst supervising the case to be present with enough frequency to detect activities within a learner’s day that may occasion relapse.

Accordingly, the likelihood of disentangling all of the conceivable causes of relapse may depend on a number of considerations including but not limited to the level of a) detail with the data collection system, b) detail and consistency of the communication system between the treatment team and the stakeholders, and c) control over environmental events in the treatment setting (e.g., a treatment room in a clinic versus classroom in a school). Nonetheless, some of the general causes of relapse may be disparate enough across relapse types that practitioners may be able to arrive at a tentative hypothesis regarding the likely source(s) of relapse. Whether using a tentative or more formal hypothesis, a reaction plan may be devised to respond to the relapsed severe challenging behavior.

Considerations for Behavior Intervention Plans

Practitioners should collaborate with clients and treatment stakeholders to to include recommendations surrounding relapse in clients’ behavior intervention plans (BIPs). Research suggests that despite recent stakeholder training on the correct implementation of the BIP, the relapse of severe challenging behavior may also result in the return of undesirable stakeholder behavior in the form of inadvertently reinforcing severe challenging behavior and withholding reinforcement for socially-appropriate behaviors such as FCRs (Mitteer et al., 2018). Therefore, the logic behind including recommendations for relapse in BIPs is to reduce the likelihood that stakeholders react impulsively to relapse (e.g., immediately reinforcing the relapsed behavior) and instead respond in a way that a) is consistent with BIP, b) maintains everyone’s safety, c) promotes appropriate behavior, d) deescalates the relapsed severe challenging behavior, and e) preserves the treatment gains that have been made up until the point of relapse. Towards those ends, including recommendations for how to respond to relapse in a BIP is similar to crisis plans that often accompany BIPs (Ennis et al., 2017; Pollard et al., 2017; Simonsen et al., 2014), except that they are intended to specifically address the management of relapsed severe challenging behavior following successful treatment.

Practitioners should develop BIP components to direct stakeholder reactions to relapsed severe challenging behavior when the supervising practitioner is absent and cannot thoroughly analyze the context of relapse immediately. Accordingly, we advise practitioners to create concise considerations to increase the likelihood that stakeholders can review therecommendations swiftly after relapse has occurred.Practitioners should consider several core components to include in their clients’ BIPs to increase the likelihood that caregivers will be prepared to respond accordingly to relapse (Table 2). The BIP should include a recommendation for stakeholders to try to identify the likely objective environmental event that triggered relapse because that information may be critical for the practitioner in deciding how to respond most effectively to relapse. For instance, if a caregiver pinpoints that their child’s severe challenging behavior reemerged when they visited a store they haven’t returned to since before treatment, even that small amount of information may help the practitioner to recognize that this instance of relapse could be renewal (Kimball & Kranak, 2022). What’s more, awareness of the circumstances that resulted in relapse may provide the practitioner with ideas for future stakeholder training and coaching.

Table 2.

Behavior Intervention Plan Considerations

Operational definition(s) of severe challenging behavior

Behavior-analytic practitioner contact information

Identify environmental event that triggered relapse (stakeholder completes)

How to manage relapsed severe challenging behavior

Safety considerations

Strategies to reduce motivation for engaging in severe challenging behavior

Actions to avoid while managing relapsed severe challenging behavior

Common situations to avoid that might trigger further relapse

Record of stakeholder's reaction to relapse (stakeholder completes)

Next, the BIP should expressly state what the stakeholder should do to manage the relapsed severe challenging behavior in a manner consistent with the treatment plan and placing safety as a priority. Recommending stakeholder behaviors that will encourage safety for everyone involved should be a first consideration. As an example, if the client’s severe challenging behavior is SIB in the form of head-hitting, the plan could specify that the stakeholder should attempt to neutrally block SIB attempts, remove hard stimuli from the environment, and put the client’s protective helmet on the client if possible and applicable (Fisher et al., 2013). The BIP should also specify how to introduce an immediate abolishing operation for severe challenging behavior and an establishing operation for FCRs and other adaptive behaviors (e.g., following adult instructions). For instance, suppose that the client’s severe challenging behavior is maintained by negative reinforcement in the form of escape from adult instructions. In this case, the plan could specify that stakeholders should implement a dense or continuous schedule of noncontingent escape (Vollmer et al., 1995) from adult instructions while also using antecedent strategies such as prompting FCRs and the high-probability (high-p) instructional sequence to encourage cooperation with adult instructions (Lipschultz & Wilder, 2017).

After providing instructions for what the stakeholder should do to manage the relapsed severe challenging behavior, the BIP should also provide details on what the caregiver should not do to manage severe challenging behavior. In most cases, the plan should advise stakeholders to refrain from providing the functional reinforcer contingent on severe challenging behavior. As previously discussed, reinforcing a relapsed severe challenging behavior will likely engender more relapse in the form of reinstatement (Mitteer et al., 2021). Accordingly, suppose stakeholders absolutely must provide the functional reinforcer to introduce an abolishing operation for the relapsed severe challenging behavior. In that case, the practitioner should encourage the stakeholder to provide that stimulus noncontingently or contingent on appropriate behavior. Of course, practitioners should temper this advice by sharing that safety should not be sacrificed to implement high-integrity extinction. Next, the BIP should instruct the stakeholder to avoid introducing additional evocative situations that might increase the likelihood of more severe challenging behavior, if possible, until the stakeholder has been in contact with the practitioner. For instance, suppose that severe challenging behavior is maintained by social positive reinforcement in the form of access to tangible items. In this scenario, the stakeholder should temporarily avoid removing preferred items or denying access to those stimuli contingent on appropriate behavior.

Including a recommendation in the BIP for stakeholders to note their exact response to relapse and communicate that information to the practitioner is valuable for several reasons. First, it would be useful to know if the stakeholder’s reaction to relapse successfully maintained safety, suppressed severe challenging behavior, and invited adaptive behavior such as FCRs. If the stakeholder’s reaction to relapse was unsuccessful, this is an opportunity for the stakeholder and practitioner to converse about what approaches worked and didn’t work so that the plan can be improved. Second, stakeholder description of their reaction to relapse can help the practitioner pinpoint if multiple forms of relapse have transpired. Finally, similar to having knowledge concerning the environmental events that lead to relapse, learning about the stakeholder’s reaction to relapse may provide further opportunities for stakeholder training. For example, the practitioner could specifically target FCR prompting strategies during future caregiver training if the caregiver shared that they had difficulty prompting the learner to engage in the FCR to access the programmed reinforcer.

Treatment stakeholders such as caregivers and teachers should actively participate in developing the BIP. Seeking stakeholder input can help a practitioner design a practical plan that is feasible to implement even in the face of competing punishing and reinforcing contingencies (e.g., social disapproval from others in community settings; Allen & Warzak, 2000). From this perspective, practitioners can use the task of collaboratively crafting the BIP as an opportunity to build stakeholder rapport and convey empathy and compassion for the stakeholder’s experiences with managing the client’s severe challenging behavior that could potentially relapse in the future (Taylor et al., 2019). Practitioners should recognize that stakeholders may perceive the conversation on the development of a BIP to mean that relapse is inevitable, which could be very challenging for the stakeholder to consider. Therefore, practitioners should approach the conversation from a place of support, validate stakeholder concerns, and highlight positive aspects of the learner’s progress (D’Agostino et al., 2023). All efforts should be made to adopt best practices in compassionate care (Denegri et al., 2023) when supporting caregivers, families, and other stakeholders in planning for relapse, paying particular attention to the importance of the therapeutic relationship (Taylor et al., 2019). As follows, the plan should be applicable across treatment environments, such as the client’s home, school, and community settings.

Safety Precautions

When considering strategies to mitigate and effectively react to relapse, practitioners should be preparing for the possibility that relapse may occur under the various circumstances outlined above. As individuals enter the generalization phase of treatment, whether it be generalization probes with novel staff, introduction to novel settings, or reintroduction to settings in which severe challenging behaviors previously contacted reinforcement, practitioners should prepare for each generalization opportunity by having a plan and the resources needed to keep everyone safe in the event that relapse occurs. Programming for and assessing the generalization of behavior change across stimulus conditions may result in renewal (Kimball & Kranak, 2022). And unfortunately, when severe challenging behavior renews due to a context change, caregivers may be at an increased susceptibility to engaging in treatment integrity errors that can trigger worsened relapse (Mitteer et al., 2018; Williams et al., 2023). Considerations should include all aspects of severe challenging behavior management, beginning with awareness that presenting these situations may evoke relapse.

A critical consideration is ensuring that all individuals involved in treatment are aware of the potential for severe challenging behavior to occur so the team can plan for appropriate generalization opportunities, discuss potential barriers, and address these identified barriers prior to beginning generalization testing. It is imperative that the staff, caregivers, or stakeholders who will be in attendance can respond according to the BIP and maintain the safety of the individual and others. As the treatment team plans for appropriate generalization opportunities or transitions, they should have a plan for how severe challenging behavior will be addressed in the specific setting (e.g., how and when should the team deliver reinforcement), as well as where the intervention will take place in the specific setting. Considerations should encompass any environmental barriers such as narrow hallways or areas that may prohibit movement, crowded areas, or areas with heavy objects that may become dangerous if the individual engages in property destruction or aggression.

The treatment team could consider visiting the generalization setting prior to attending with the individual and determining how to best navigate the setting in the case that severe challenging behavior occurs. The treatment team should discuss what proactive and reactive strategies might be used to minimize injury to self or others in the specific environment. Proactive strategies may include basic antecedent manipulations (Cooper et al., 2020), such as staying between the client and others at all times while out in the community, keeping a safe distance between the client and others at all times, staying within arms’ reach of the client at all times, and always having an available escape route to transition the client through.

Reactive strategies may include the basic reactive strategies that the treatment team typically implements, such as crisis prevention and management tactics, as well as specific reactive strategies that may need to be implemented due to any environmental barriers that have been identified. The treatment team should discuss these barriers and the potential necessary responses, including responding to others if anyone who is not trained attempts to intervene, how to direct caregivers or others in the case that relapse occurs, or responding in the event that the individual attains something that is potentially dangerous to themselves (e.g., a non-edible item in a store when a form of the severe challenging behavior includes pica) or to others (e.g., an item that can be used as a weapon). Additional discussion and practice should include strategies and contingency plans if the original plan is not able to be implemented, and specific criteria of when to implement the contingency plan to be able to respond efficiently.

Using the team’s identified strategies, staff and caregiver training should be conducted. All individuals who will be present during the generalization opportunity should receive training on proactive and reactive strategies that will be utilized in the generalization context. Ensuring staff and caregivers are well versed in the BIP and have practiced before entering the target setting will likely result in more effective interventions. Discussion of proactive and reactive strategies alone is not sufficient. Rather, extended training should be implemented (e.g., behavioral skills training; Parsons et al., 2012), including fluency training, to address the occurrence of severe challenging behavior across generalization settings.

During generalization opportunities or probes, having an appropriate number of staff available to be able to respond to the severe challenging behavior will be critical to ensure the success of the intervention. This may include ensuring there are two well-trained staff available during the probe, or if not, having a trained practitioner such as a BCBA present during the probe. If there is only one staff member available, the staff member should be aware of the best tactics to prevent injury, and should have had a chance to practice implementing these tactics. Additionally, the staff members should practice reacting to severe challenging behavior with caregivers or other stakeholders who will be present during the generalization opportunity. If caregivers are conducting a generalization probe or are attempting to attend a new activity or novel location, caregivers should wait until an additional caregiver is available to attend and assist. Additionally, these generalization opportunities should only be implemented by caregivers who have had extensive training and practice with responding to severe challenging behavior according to the BIP.

A further safety consideration for generalization opportunities that could result in relapse includes having protective equipment and protective padding (e.g., blocking pads to block head banging) readily available. Having protective equipment quickly and readily available will assist in decreasing the likelihood of injury to the client or others and may increase the confidence of staff or caregivers in their ability to respond effectively to severe challenging behavior. It is imperative to increase protective equipment for staff, caregivers, and the individual, if needed, to the extent that will keep everyone safe in the case that severe challenging behavior occurs. Training for the staff and caregivers should include retrieving and utilizing the protective equipment within the context of the environmental barriers that may be present during generalization probes.

Conclusion

In the last decade, the emergence of translational and applied research demonstrating relapse in socially significant behavior has provided evidence that practitioners need to use and apply the information within their practice (e.g., Falcomata et al., 2018; Kimball & Kranak, 2022; Mace & Critchfield, 2010; Muething, et al., 2022; Podlesnik et al., 2017; Pritchard et al., 2014; Wathen & Podlesnik, 2018). This need is further underscored by item H.5. of the upcoming 6th Edition TCO (BACB, 2022). Here, it specifies that behavior analysts must “Plan for and attempt to mitigate possible relapse of the target behavior.” By placing this item on the TCO, our national certifying body is not only endorsing, but requiring that, by 2025, practitioners of behavior analysis be well-versed at identifying and remedying relapse of severe challenging behavior. The current paper addresses this itemby providing areas for practitioner awareness and some potentially useful strategies for reacting to relapse, which may assist in making clinical decisions related to relapse. This information serves as a foundation upon which practitioners can begin to understand, identify, and react to relapse.

While this paper provides a foundation, it is only that. Figure 1 is not intended to function as a decision-making model (e.g., Berg et al., 2016; Geiger et al., 2010; Grow et al., 2009; LeBlanc et al., 2016) for selecting actions when reacting to relapse. Instead, we merely wish to equip practitioners with reactive options to consider when relapse occurs. The development and empirical validation of a decision-making model for reacting to relapse is beyond the scope of this paper, and completing such tasks would likely require years of future research. Nonetheless, perhaps this paper's contents can serve as a starting point for practitioners until such a model is published. We also hope that this paper serves as a call to action, for researchers in relapse to continue to work towards making their studies as accessible to practitioners as possible, and for practitioners to seek out, learn from, and use the evidence base on relapse within day-to-day service delivery. Through these actions, applied behavior analytic interventions will be even more effective, helping to change the lives of those in need in the future.

Data Availability

We did not analyze or generate any datasets because our work is a discussion and review article.

Declarations

Conflicts of Interest

The authors have no conflicts of interest to disclose.