State of the Science: Psychotherapeutic Interventions for Prolonged Grief Disorder

Abstract

Prolonged grief disorder (PGD) is a distinct diagnostic entity that has recently garnered considerable attention as it describes an intense, enduring, distressing and disabling bereavement reaction experienced by a small minority of community-based mourners. In recent decades, research has exploded to address how best to treat PGD with different psychotherapeutic interventions. In this state-of-the-science review, the strength of the evidence will be discussed regarding common psychotherapeutic interventions used to treat grief. Specifically, we focus on the most commonly used interventions, cognitive behavioral (CB)-based therapies, bereavement and support groups, and brief contact interventions (BCIs), in an effort to summarize the relevant clinical takeaways of the current available research. A discussion of the use of these therapies in specific clinical populations is also included, with a focus on those traumatically bereaved, pediatric populations, communities of color, and underserved communities. Important foci and directions for future research are also discussed.

Prolonged grief disorder (PGD; also in the past referred to as complicated grief and persistent complex bereavement disorder), characterized by intense longing/yearning for and preoccupation with a deceased loved one, has recently been added to the International Classification of Diseases (ICD-11) (World Health Organization, 2023) and the Diagnostic and Statistical Manual of Mental Disorders (5^th ed., text rev.; DSM-5-TR; American Psychiatric Association, 2022). Symptoms (e.g., emotional pain, identity disruption, avoidance of reminders of the death) cause clinically significant distress or functional impairment and must be present more than 6 months post-loss in the ICD-11 and more than 12 months post-loss in the DSM-5-TR (6 months for children and adolescents). PGD is associated with poor outcomes including suicidal thoughts and behaviors and lower quality of life, as well as other distinct mental disorders, including depression, anxiety, and posttraumatic stress disorder (PTSD) (Boelen & Prigerson, 2007; Komischke-Konnerup et al., 2021; Latham & Prigerson, 2004).

Given the distinctness of PGD from other mental disorders, its association with physical impairment, pain, and suicidal ideation (Prigerson et al., 2021), and the prevalence of the condition (prevalence varies somewhat by study but a conservative estimate is likely 3–4%, depending on which diagnostic criteria is used, ICD-11 vs DSM-5-TR [Rosner et al., 2021]), consideration must be taken as to what treatments work best for PGD and the global population who suffer from this disorder.

Given the relatively recent official recognition of PGD and the variance in diagnostic criteria between the ICD-11 and DSM-5-TR, the existing literature examining psychotherapeutic interventions for PGD is variable in its approach to measuring and assessing grief levels, although assessing for PGD has become more common. In a 2008 review of all studied psychotherapeutic interventions (ranging from professional counseling to crisis intervention to support groups) for bereaved persons (not necessarily meeting criteria for PGD), the authors found a small positive effect favoring intervention immediately posttreatment (mean effect size: 0.16 for randomized studies, 0.51 for nonrandomized studies) but no significant findings at follow-up supporting intervention (Currier et al., 2008) (see Table 1 for a summary of review articles appearing in the text). But, in those grievers with “marked difficulties adapting to loss,” they found better outcomes from psychotherapeutic interventions, concluding a relationship between level of grief distress and likelihood of successful therapeutic outcomes, suggesting that focusing interventions on those with significant symptom burden may be more efficacious (Currier et al., 2008). Notably, only one study included in the review screened for complicated/prolonged grief (Wagner et al., 2006). In 2011, a meta-analysis on the treatment of complicated grief looking at the existing randomized control trials on therapeutic interventions concluded that treatment interventions (but not preventive ones) for complicated grief had significant positive effects immediately posttreatment and even stronger effects at follow-up, although only one study assessed for longer-term treatment effects at 6 months out (Boelen et al., 2007; Wittouck et al., 2011). In this review, studies of treatment interventions, performed 3–14 months post-loss, all assessed for complicated grief.

Table 1.

Summary of Reviews

Review article	Bereavement therapy studied	Summary of findings
Currier et al. (2008)	All psychotherapeutic interventions	Small positive effect favoring intervention immediately posttreatment. No positive effect of interventions at follow-up. Better outcomes for those with “marked difficulties adapting to loss.”
Wittouck et al. (2011)	Preventive and treatment psychotherapies	No positive effect of preventive CBT interventions on PGD development. Moderate efficacy for treatment CBT interventions in those with significant clinical symptoms.
Currier et al. (2010)	CBT compared to non-CBT psychotherapies	CBT outperformed non-CBTs and no treatment controls for PGD, depression, anxiety, and PTSD.
Wagner et al. (2020)	Internet-based psychotherapies (all included were CBTs)	Internet-based CBT interventions had moderate to large effects on PGD symptoms and PTSD, with smaller effects on depression.
Komischke-Konnerup et al. (2024)	CBTs	CBT showed statistically significant medium pooled effects on PGD symptoms. “Moderate” evidence to support efficacy of grief-focused CBTs over other psychotherapies for PGD.
McGill et al. (2022)	Brief contact interventions	BCIs for bereavement reduced grief, depression, and improved well-being, with small to medium positive impacts.
Maass et al. (2022)	Support/bereavement groups	Bereavement groups were slightly more effective than control group immediately post-treatment, but effects did not persist at follow-up, yielding “weak” evidence supporting their use.
Hanauer et al. (2024)	Psychotherapy in children/adolescents	Psychosocial interventions in pediatric patients likely do clinically improve grief symptoms.
Saladino et al. (2024)	CBTs in children/adolescents	CBT is effective for PGD in pediatric populations, with medium to large effect sizes.

Note. Articles are organized by order of appearance within the text.

In the last decade, the number of reviews and meta-analyses on PGD treatment have multiplied, especially in light of the global pandemic (Johannsen et al., 2019; Linde et al., 2017; Martínez-Medina & Rodríguez-Orozco, 2023; Mason et al., 2020; Shear, 2015; Szuhany et al., 2021). To address this growing body of literature, we have categorized our article into subcategories focusing on commonly used therapies for grief, including cognitive-behavioral approaches, support/bereavement groups, and brief contact interventions for bereavement. We have also looked at populations that may require specific consideration, including traumatically bereaved individuals, children and adolescents, communities of color, and underserved communities.

In this state-of-the-science review (Comer, 2024; this issue), our goal is to provide a go-to resource for clinicians treating patients suffering from PGD, to summarize the most recent literature, weigh the evidence, and provide an update on the directions for future research.

Cognitive Behavioral Therapy (CBT) Approaches

TREATMENT PARADIGM

Overall, CBTs for prolonged grief aim to address bereavement-related distress by increasing adaptive coping via introducing and practicing various techniques and honing coping skills. CBTs for prolonged grief usually include two components of CBT, with exposure, cognitive restructuring, and behavioral activation being the most commonly incorporated components (Komischke-Konnerup et al., 2024). Regarding delivery, CBTs for prolonged grief have been implemented in individual and group settings (86% individual vs 14% group) and via in-person and online modalities (55% in-person vs 45% online), lasting on average 12 sessions, on a weekly basis (Komischke-Konnerup et al., 2024). Although CBTs for prolonged grief share common characteristics, many incorporate non-CBT components. For example, prolonged grief disorder therapy (PGDT; formerly complicated grief therapy) is a subset of CBT therapy containing elements of CBT for posttraumatic stress disorder (PTSD) and interpersonal therapy (IPT) for depression (Boelen et al., 2006; Mauro et al., 2022; Shear et al., 2001). This manual-guided therapy was designed to last approximately 16 sessions over 4 months with the goals of treatment being to decrease grief intensity, increase ability of the participant to enjoy memories of the deceased, and reengage with daily life and social groups (Shear et al., 2001). In 2011, an integrative CBT manual was developed for complicated grief disorder (CG-CBT) lasting 20–25 sessions with three phases that incorporate a variety of treatment strategies, including core CBT aspects such as cognitive restructuring and confrontation (Rosner et al., 2011). Of note, CG-CBT incorporates techniques from non-CBT therapeutic approaches including Gestalt Therapy, Solution Focused Brief Therapy, Multigenerational Family Therapy, and relaxation and imagery techniques.

CONCEPTUAL AND THEORETICAL UNDERPINNINGS

In the conception of PGDT in 2001 by Shear and colleagues, they based their therapy on the dual process model of coping with bereavement, which divides stressors into loss- and restoration-oriented groups and describes an oscillation between these stressors to either confront or avoid grief. Addressing this oscillation allows for adjustment over time in healthy mourning (Stroebe & Schut, 1999). Stroebe and Schut propose that complicated grief (or prolonged grief) is an absence of this oscillation (getting stuck with stressors on either side), preventing adjustment to the loss (Stroebe & Schut, 1999).

Other CBTs for prolonged grief have been informed by the cognitive-behavioral conceptualization of PGD, which involves three interrelated core processes that feed into and maintain the presence of prolonged grief, and each other: poor integration of the knowledge of the loss, negative global beliefs and misinterpretation of grief reactions, and maladaptive avoidance strategies (Boelen et al., 2006). The cognitive-behavioral conceptualization of PGD is focused on addressing these core processes by helping to process and integrate the loss, helping to identify negative beliefs and interpretations and challenge or change them, and helping to replace maladaptive coping strategies with more productive ones (Boelen et al., 2006). The CBT components of exposure, cognitive restructuring, and behavioral activation can be utilized to target these three core processes.

RESEARCH AND SUPPORTING EVIDENCE

The extant literature has examined PGD interventions from both prevention and treatment approaches. Interventions from both approaches are primarily based in CBT. In terms of prevention, a meta-analysis of preventative CBT interventions for PGD revealed no positive effect of preventive CBT interventions on PGD development (Wittouck et al., 2011). Of note, the authors of this meta-analysis indicate that there may be subpopulations of grievers that would benefit from preventive interventions, and the reviewed studies have not demonstrated efficacy due to a lack of identifying the appropriate target groups (Wittouck et al., 2011). The same meta-analysis found moderate efficacy for prolonged grief treatments—in those with significant clinical PGD symptoms—both short- and long-term, including five studies, four which showed positive results, all four of which utilized cognitive-behavioral techniques (Wittouck et al., 2011). In line with the findings of this meta-analysis, an RCT examining a preventive group-based CBT intervention for PGD in individuals bereaved by suicide did not outperform a no-treatment control group (Wittouck et al., 2014). However, another RCT examining an internet-based, therapist-assisted cognitive-behavioral prevention intervention called Healthy Experiences After Loss (HEAL), in individuals bereaved by cancer, found reductions in prolonged grief and lower incidence rates following intervention (Litz et al., 2014). More research examining targeted preventative and early interventions for PGD appears warranted.

Regarding treatments for PGD, the first randomized control trial (RCT) of PGDT in bereaved persons was in 2005, performed by the group who first developed a targeted cognitive behavioral grief therapy (Shear et al., 2005). Sixteen sessions of PGDT were compared to 16 sessions of IPT. Although both treatments led to positive effects in grief symptoms, response rate (defined as a decrease in Inventory of Complicated Grief score of 20 or more points) was significantly higher for the PGDT group (51%, n = 49) compared to the control IPT group (28%, n = 46) (Shear et al., 2005).

A 2010 review of 11 studies, which was a follow-up to the 2008 review from the same group on all psychotherapeutic interventions (Currier et al., 2008), comparing CBT interventions to non-CBT interventions for bereavement, found CBT outperformed non-CBT and no-treatment controls across a wide variety of psychological symptoms (PGD, depression, anxiety, PTSD), but notably only three of the studies assessed for PGD symptoms, limiting the generalizability of these findings (Currier et al., 2010).

In 2016, a review on the treatment for complicated grief concluded that in-person and internet-based CBT was most effective in targeting complicated grief, but called for further investigation into how and for whom the treatment best helps (Doering & Eisma, 2016). Notably, this study focused on summarizing the literature on PGDT after concluding that more grief-tailored psychotherapeutic interventions (like PGDT) are superior to classical depression treatments like interpersonal therapy, which historically have not shown promising results at targeting bereavement intensity in clinical trials (Reynolds et al., 1999).

In the 2010s, studies of CBT for grief exponentially increased in number. Some compared CBT to waitlist control groups (Eisma et al., 2015; Kersting et al., 2013; Litz et al., 2014; Papa et al., 2013; Rosner et al., 2014), while others compared CBT grief therapies to interpersonal therapy or supportive counseling (Boelen et al., 2007; Nam, 2016; Shear et al., 2005, 2014). Notably, Nam’s study comparing CBT to supportive counseling examined whether a supportive person brought to CGT sessions and provided psychoeducation on grief helps with PGD symptom resolution, and they found this social support had positive effects (Nam, 2016). In 2016, Shear and colleagues did a larger RCT of CGT [PGDT] combined with either placebo or citalopram to follow-up their 2005 study, concluding that CGT/PGT is the “treatment of choice” for PGD, leading to significant improvement in grief symptoms compared to placebo and outperforming citalopram (Shear et al., 2016). Studies have also shown that the improvements in PGD symptoms are long-lasting after CB grief therapies, maintaining symptom reductions up to a year and a half out from treatment cessation (Rosner et al., 2015). Additionally, it has been suggested that CBT may benefit those with more severe grief symptoms more than those with more mild symptoms; according to one study in those recently bereaved from suicide, those with higher levels of suicidal ideation had greater reductions in grief symptoms compared to participants with lower suicidal ideation (de Groot et al., 2010).

A 2020 meta-analysis focused on internet-based therapies for PGD ended up including only studies of CBT interventions and found moderate to large effects on symptoms of PGD and PTSD, with a smaller effect seen for depression, across seven studies (Wagner et al., 2020). Observed effects were stable through follow-up. Number of treatment sessions was found to be a moderator of grief symptoms, with higher numbers of sessions proving more effective (Wagner et al., 2020). In a 2021 overview of PGD, the authors describe CGT (PGDT) as a “gold-standard intervention” for PGD, although the study did not include systematic analysis or meta-analysis to support this statement (Szuhany et al., 2021).

The goal of an updated 2024 review on grief-focused CBTs was to establish the “overall efficacy” of CBT for PGD in adults (Komischke-Konnerup et al., 2024). The authors included 22 RCTs with over 2,900 participants, 86% women. Sixty-four percent (14 studies) had passive control condition, 4 studies with active control condition (e.g. supportive counseling) and 4 studies with competing control (e.g., IPT) (Komischke-Konnerup et al., 2024). Only 13 out of 22 studies included participants based on the 6-month time criterion for PGD, and only 14 out of 22 studies included participants based on cutoff PGD values (Komischke-Konnerup et al., 2024). All studies assessed PGD symptoms (this was an inclusion criterion), but using various versions of the scale (i.e., Inventory of Complicated Grief, Prolonged Grief Inventory-13, Traumatic Grief Inventory) (Komischke-Konnerup et al., 2024). CBT pooled effect size was medium immediately posttreatment (g = 0.65) and large at follow-up (g = 0.90), with a medium effect size or larger across all subgroups of studies (Komischke-Konnerup et al., 2024). The authors also found medium effect sizes for PTSD and depression symptoms and a small effect size for anxiety at postintervention (Komischke-Konnerup et al., 2024). At follow-up, only pooled effect size for anxiety (not PTSD or depression) reached clinical significance (Komischke-Konnerup et al., 2024). Unfortunately, all studies had at least some concerns of bias, and two were deemed overall “high risk” of bias, as agreed upon by two independent reviewers, due to missing outcome data and deviation from the intended interventions (Komischke-Konnerup et al., 2024). High heterogeneity (high I² values) was observed across many of the observed outcomes. The authors explored possible explanations for heterogeneity and none of the moderators reached statistical significance, although a trend was seen toward greater efficacy of CBTs when inclusion criteria for the study included a clinically relevant level of PGD symptoms (p = 0.055) (Komischke-Konnerup et al., 2024). Overall quality of meta-analytical evidence was “moderate”; some indications of inconsistency (high heterogeneity and inability to identify statistically significant causes) and “indirectness” (8/22 studies did not include participants with clinically significant PGD symptoms at pre-intervention) (Komischke-Konnerup et al., 2024). The overall effect of CBT remained statistically significant, even when accounting for publication bias (Komischke-Konnerup et al., 2024). Importantly, when CBT was compared to both wait list control and active/competing control conditions, CBT still had statistically significant medium pooled effects on PGD symptoms (Komischke-Konnerup et al., 2024). Overall, the meta-analysis concluded that there is “moderate” evidence to support the efficacy of grief-focused CBTs over other psychotherapies (IPT, SC) for PGD, with evidence also supporting their use for PTSD, depression, and (to a lesser extent) anxiety among distressed bereaved persons (Komischke-Konnerup et al., 2024).

In trying to understand CBT’s effectiveness for treating PGD, work has been done to understand what components of CBT make it superior to other treatments. Komischke-Konnerup and colleagues found a large pooled effect for CBTs without exposure versus a medium pooled effect for CBTs with exposure, an unexpected finding suggesting that exposure may not be as powerful as previously thought (Komischke-Konnerup et al., 2024). In addition, the authors found that many CBT components did not moderate the overall positive effect, and the largest pooled effect was found for studies with only one key CBT component included in the therapy, which they made sense of based on the cognitive-behavioral conceptualization of CBT as proposed by Boelen (Komischke-Konnerup et al., 2024). This conceptualization suggests that targeting just one core process of PGD would have carry-over effects to other core processes not directly targeted (Boelen et al., 2006; Komischke-Konnerup et al., 2024). No studies compared individual to group CBT formats, but both formats were found to reduce PGD symptoms significantly when study findings of each were pooled (Komischke-Konnerup et al., 2024). Also important to note in a world increasingly tied to the internet, especially in the context of telemedicine’s popularity, was that whether CBT was dispensed digitally versus in person did not alter the effect on PGD symptoms (Komischke-Konnerup et al., 2024). Interestingly, the authors noted that digitally delivered CBTs were more often compared to passive control group (possibly inflating effect sizes) whereas in-person CBTs were often compared to active/competing control groups (Komischke-Konnerup et al., 2024). Also notable was that number of sessions, regardless of treatment delivery modality, did not appear to moderate effect size of CBTs (Komischke-Konnerup et al., 2024). Some work has also been done to explore whether mindfulness components may improve outcomes in PGD. A recent RCT found that grief-focused CBT over 11 weeks outperformed mindfulness-based cognitive therapy for both PGD symptomatology and depression scoring, although mindfulness may still be a valuable tool in grief therapy (Bryant et al., 2024).

In considering using grief-focused CBTs for PGD, understanding which groups will respond best is important for treatment outcomes. Komishke-Konnerup and colleagues addressed this question in their study, concluding that age and gender of the sample did not affect CBT efficacy, although notably only 13% of the sample from included studies were men (Komischke-Konnerup et al., 2024). Studies that had clinical cutoffs for PGD symptoms and applied the 6-month criterion had a larger pooled effect on grief than those that did not, although broader inclusion criteria (studies that included symptoms of PGD, PTSD or depression) also reported large effects on PGD symptoms (Reitsma et al., 2023; van Denderen et al., 2018). The authors also note that CBTs had a smaller effect on PGD symptoms when the cause of death was unnatural (i.e., sudden, unexpected, or violent) compared to natural, possibly due to more complex grief-trauma reactions and co-occurring PGD, PTSD and depressive symptoms (Komischke-Konnerup et al., 2024).

Finally, to address a subcategory of CB grief therapy, CB-existential grief interventions have been explored minimally in the literature. An open trial in parents bereaved after losing a child to cancer of meaning-centered grief therapy, a manualized one-on-one 16-session intervention, found promising results (significant improvements in prolonged grief at post-intervention and follow-up) in a small sample of only 6 completers (out of 8 parents who started the intervention) (Lichtenthal et al., 2019). A similar pilot RCT of group metacognitive grief therapy, a 6-session 2-hour/week intervention, also found promising results (significant PG symptom reductions that remained at 3- and 6-month follow-up) in the initial 12-participant cohort (Wenn et al., 2019). These preliminary results suggest promise for this CB-based approach to PGD treatment, pending larger trials.

FUTURE RESEARCH DIRECTIONS

Future research on grief-focused CBT should focus attention on key areas lacking in the current literature. One notable problem in the current research is the heterogeneity in how grief is being measured and how PGD is diagnosed. Even between ICD-11 and DSM-5-TR, there are key differences in diagnosis. To heighten uniformity across studies, cross-nationally validated instruments (e.g., the PG-13-R) should be used to promote uniformity across studies (Komischke-Konnerup et al., 2024; Prigerson & Maciejewski, 2024). Having a criterion-standard approach for both diagnosing PGD and measuring grief symptoms would help to better determine the efficacy of these treatments. Future research should have an agreed upon way to measure grief symptoms in a valid and reliable way, so that future meta-analyses can draw stronger conclusions.

Another important problem noted across studies is that even among trials of CBT treatments found to be effective at reducing PGD symptoms, 47%–56% of individuals are still experiencing PGD symptoms at clinically relevant levels post-intervention (Komischke-Konnerup et al., 2024; Lacasta & Cruzado, 2023; Reitsma et al., 2023). This suggests the field needs to work to find even better treatments, possibly capitalizing on the effective components of grief-focused CBT, perhaps doing away with the less effective components (e.g., exposure in the context of deaths from nontraumatic causes), and adding more promising components (e.g., pharmacotherapies) to the armamentarium to address PGD symptoms. This will require more high-quality RCTs on CBT-based and other therapies to address impairing bereavement-related distress in general and PGD in particular.

Finally, as shown by the recent meta-analysis (Komischke-Konnerup et al., 2024), the studies examining CBT demonstrate significant heterogeneity in intervention format, delivery, and population. Future research needs to address which intervention components work best for which groups. Given the decreased efficacy of CBT for PGD symptoms in cases of unnatural death (Komischke-Konnerup et al., 2024), it may be necessary to target treatment interventions by cause of death. Additionally, no studies directly compare the effects of group to individual format CBT. Such information could significantly impact implementation and dissemination efforts to increase the reach and access of therapy for PGD. Similarly, to determine when the most benefit from CBT treatment for PGD occurs (optimal time criterion for effective treatment), more research regarding intervention timing within the grieving process is needed. Research should continue to address whether the mechanism of the loss (i.e., unnatural versus natural) should determine CBT treatment components and whether combining psychotherapeutic approaches with medication management maximizes therapeutic benefit, especially in cases of unnatural loss at higher risk for PGD development (Djelantik et al., 2020).

Web-Based Therapy Interventions

It is important to note the shift of treatment from being fully in-person to being increasingly digital/online, especially in the context of the COVID-19 pandemic, which is reflected in many studies (Acierno et al., 2021; Eisma et al., 2015; Kaiser et al., 2022; Kersting et al., 2013; Lenferink et al., 2023; Litz et al., 2014; Reitsma et al., 2023; Treml et al., 2021; van der Houwen et al., 2010; Wagner et al., 2022; Wagner et al., 2006). One notable example of a COVID-19 bereavement study is Dominguez-Rodriguez et al., a waitlist-controlled RCT of an unguided web-based intervention for PGD in adults who lost a loved one between December 2020 and November 2021 (Dominguez-Rodriguez et al., 2023). They found that, although intervention completion rates were low (39.5%), treatment led to significant symptom reduction in grief, depression, posttraumatic stress, hopelessness, anxiety, and suicide risk, with high levels of user satisfaction (Dominguez-Rodriguez et al., 2023). More generally, in a systematic review and meta-analysis of internet-based bereavement care from 2020, all the included studies were cognitive-behavioral-based therapies (Wagner et al., 2020). As already noted above, the most recent meta-analysis on CBT-based grief interventions did not find that digitally delivered versus in-person-delivered CBT therapy was more effective than face-to-face (Komischke-Konnerup et al., 2024), although previous reviews have found stronger evidence supporting in-person interventions (Johannsen et al., 2019). This is all promising for web-based interventions, which will likely increase the number of people who can be reached globally and can increase accessibility of grief treatments (Ramos et al., 2024).

Brief Interventions/Brief Contact Interventions

TREATMENT PARADIGM

Brief (contact) interventions (BCIs) are made up of any type of health support delivered with minimal contact, via written material (e.g. emails, webpages) or short phone calls, either one time or over a limited period of time (McGill et al., 2022). They are designed to deliver information, knowledge, and skills to manage health problems and increase health literacy, with a focus on self-management/self-empowerment and healthy behaviors; therapeutic content may or may not be included (McGill et al., 2022). New research has focused on targeting BCIs towards the bereaved, after success with reducing anxiety and depression (Newman et al., 2011), self-harm (Milner et al., 2015), and alcohol consumption (Beyer et al., 2018), to see if they may be helpful in this context.

CONCEPTUAL AND THEORETICAL UNDERPINNINGS

BCIs are thought to be beneficial in bereavement because they require extremely low time commitment, have high flexibility, require minimal resources to reach large populations, and they reach out preemptively to those who might be suffering or at risk but are unable or unwilling to ask for help (McGill et al., 2022). These may turn out to be key interventions in helping to acknowledge and process loss for those at risk of PGD, for whom preventive intervention has not worked well (Wittouck et al., 2011).

RESEARCH AND SUPPORTING EVIDENCE

McGill et al. completed a systematic review on BCIs for bereavement, in which they identified 15 articles describing 12 intervention trials, overall finding a small to medium positive impact (Cohen’s d = 0.2–0.5) from interventions with reductions in grief, depression, and improved well-being (McGill et al., 2022). Notably, not all interventions were considered helpful and one (involving a condolence letter) increased depression 6 months out (McGill et al., 2022). These interventions were diverse, ranging from condolence letters to coping resources/psychoeducation to invitations to hospital memorial services to short-term phone calls/counseling support, delivered generally within the first 6 weeks after the loved one’s death (McGill et al., 2022). Across these studies, there were no common measures of grief, only 9 studies used a control group, and few studies measured efficacy and safety with enough power, limiting the generalizability of these findings (McGill et al., 2022).

A new study on a BCI is the EMPOWER multi-site pilot trial, which can be administered both pre- and post-loss in an attempt to try to reduce psychological distress in surrogate decision-makers of critically ill patients using an ultra-brief (~2 hour) 6-module flexible manualized psychological intervention (Lichtenthal et al., 2024). EMPOWER showed high completion rates and satisfaction among users, and decreased grief intensity, PTS and depression at 3 months out, suggesting preliminarily that these brief interventions can be quite valuable compared to a control group that received “enhanced usual care”—the standard emotional support provided by staff with additional resources for caregivers (Lichtenthal et al., 2024). Another notable BCI that focused on the bereaved was an open trial of Skills for Psychological Recovery (SPR), a brief (up to 5 sessions) early intervention for adult sudden loss survivors within 1 year of the sudden death (Williams et al., 2024). SPR showed promising results reducing PTS, depression, and grief reactions at post-intervention and follow-up (3 months out), although the study lacked a control group (Williams et al., 2024).

FUTURE RESEARCH DIRECTIONS

More research has been called for on BCIs for grief to discover who is most likely to benefit from BCIs, what settings BCIs are best to be delivered in, and any possible risk for unintended negative effects (McGill et al., 2022). As for interventions like EMPOWER and SPR, larger RCTs will need to be done to verify their efficacy, but preliminary results are promising.

Support/Bereavement Groups

TREATMENT PARADIGM

Bereavement groups are quite common interventions for those who are grieving (Maass et al., 2022). According to a 2022 review of bereavement groups, the average bereavement group lasts 10 sessions over 10 weeks with each session lasting 90–120 minutes (Maass et al., 2022). Of the 4 included studies that specified group size, the groups were small, with fewer than 10 members, and the groups were led by a variety of professionals, including mental health nurses, psychologists, researchers, psychotherapists, social workers, and counselors. Most of the studies (79%) used a treatment protocol to conduct the sessions (Maass et al., 2022).

CONCEPTUAL AND THEORETICAL UNDERPINNINGS

The concept behind using bereavement groups for PGD is that low social support is a risk factor for PGD (Burke & Neimeyer, 2013); therefore, bereavement groups can provide that missing social and emotional support and reduce social isolation by providing a sense of community, as well as providing information and advice exchange between mourners (Maass et al., 2022). Advantages to bereavement groups include social interaction, a place to open up about thoughts and feelings, normalization of grief reactions, and the sharing of hope and coping strategies among mourners. Disadvantages include development of unhelpful group dynamics, competition between group members, poor structure/organization/lea dership, and increased distress from listening to others’ stories (Dyregrov et al., 2013; Maass et al., 2022). It has been proposed that the negative effects of bereavement groups can be mitigated by carefully screening candidates, providing specialized treatment in complicated grief cases (like suicide), and encouraging homogeneous and closed groups (i.e., those grieving a child, or those grieving after suicide would be grouped together) (Dyregrov et al., 2013).

RESEARCH AND SUPPORTING EVIDENCE

In a 2019 review on psychological interventions for grief, they noted that individual format interventions outperformed group format interventions in relation to effect sizes, even when controlling differences in study quality and baseline symptomatology (which were noted to be different between studies on individual versus group therapy) (Johannsen et al., 2019). Despite this, they urged caution as fewer of their studies included group-based interventions and none compared individual to group therapy formats (Johannsen et al., 2019). In 2021, a review on PGD treatments concluded that not enough research has been conducted on support and bereavement groups to draw major conclusions on their efficacy for long-term outcomes in PGD, noting they may be more helpful immediately after the loss (Szuhany et al., 2021).

In 2022, a systematic review on effects of professionally guided bereavement groups used for grief and depression was performed, which included 14 studies (RCTs), only 5 of which were deemed to be of good quality (Maass et al., 2022). Bereavement groups were found to be “marginally more effective than control groups” immediately posttreatment and then were not more effective at follow-up (effects did not persist). They deemed the evidence supporting bereavement groups for grief to be “weak,” although noted high heterogeneity in interventions and controls groups, as well as variability in study quality (Maass et al., 2022). Notably, they observed no difference between tertiary interventions (in those with severe psychopathology like PGD) and secondary interventions (in any bereaved person) (Maass et al., 2022). Overall, the evidence does not seem to support the use of bereavement groups for PGD, although there is not much evidence to draw upon. It is important to note that there were some bereavement group studies that included CBT techniques, making it difficult to separate the conclusions drawn from this meta-analysis versus those drawn in the CBT section.

FUTURE RESEARCH DIRECTIONS

More studies need to be performed comparing individual and group therapy, and larger studies need to be done on bereavement and support groups with higher quality study design. Specifically, Maass and colleagues call for research that includes clear eligibility criteria for participants, bases bereavement group content on clearly proposed theoretical frameworks, defines groups clearly as for those with psychopathology (like PGD) versus for those generally grieving, explains clearly how different treatment elements are considered, provides adequate training to group leaders, and clearly states how both treatment and control interventions conceptually differ so that conclusions can be drawn about intervention characteristics (Maass et al., 2022).

Specific Clinical Populations

Although the conclusions about the psychotherapies described so far can likely apply to diverse patient populations, there are some patient populations that may require different or modified consideration in the treatment of PGD. One such group is bereaved parents, for whom there is minimal evidence supporting particular treatment interventions, although some have called for more attention to treating this group (Dias et al., 2019; Endo et al., 2015). Other groups include those bereaved by trauma, pediatric populations, communities of color, and underserved communities, all of which will be addressed in the following sections.

TRAUMATICALLY BEREAVED

Traumatically bereaved individuals are considered at heightened risk for PGD, with research indicating nearly half of individuals bereaved by sudden and violent deaths experience PGD (Djelantik et al., 2020). The traumatic bereavement literature often focuses on deaths that are sudden, unexpected, and/or violent (e.g., suicide, homicide, accident, natural disaster, substance overdose, sudden illness). In one waitlist-controlled RCT of an online CBT therapy for PGD after traumatic loss (traffic accidents), the authors found that the intervention dramatically reduced PG, PTS, and depression symptoms compared to controls, with effects persisting at follow-up (Lenferink et al., 2023). Similarly, an RCT on homicidally bereaved individuals were found to benefit after an 8-session CBT and eye movement desensitization and reprocessing (EMDR) intervention, with reductions in both PTS and complicated grief symptoms (van Denderen et al., 2018). In a 2021 review of concurrent treatments for PTSD and PGD, standard interventions were generally effective at treating both disorders (7 out of 10 studies included with pre-post change and follow up data), which are more likely to both be present in the traumatically bereaved (Eddinger et al., 2021). Interestingly, treatment effect sizes were noted to be larger for PTS versus grief symptoms (Eddinger et al., 2021). This has important treatment implications for this group, as one treatment may be able to address both disorders. The authors call for RCTs that standardize the evaluation of PTSD and PGD symptoms in order to better address this question (Eddinger et al., 2021). Finally, a 2019 systematic review on interventions for those bereaved from suicide found that efficacious complicated grief interventions were lacking with mixed, inconsistent results across only a few existing studies on grief outcomes (Andriessen et al., 2019). Overall, there needs to be more research on traumatic loss to understand how to best help this high-risk and diverse group of bereaved people.

CHILDREN AND ADOLESCENTS

PGD presents differently in children and adolescents compared to adults, and there is disagreement on how to diagnose and assess symptoms of PGD in those under 18 years, as different criteria for diagnosis are needed but tools are lacking (Dyregrov & Dyregrov, 2013; Kaplow et al., 2018). Different from adult populations, a developmentally informed perspective needs to be taken when applying PGD criteria in children (Kaplow et al., 2012). Two recent reviews were performed, one on the effectiveness of CBT for PGD in children and adolescents and the other on the effectiveness of all psychosocial interventions for PGD in children and adolescents (Hanauer et al., 2024; Saladino et al., 2024). Hanauer and colleagues was a follow-up to a 2007 review by Currier and colleagues, which found a nonsignificant effect size among the 13 studies included, and a 2010 review by Rosner and colleagues, which found among the 27 studies included small to moderate effect sizes, with larger effect sizes seen in those with more severe symptomatology (Currier et al., 2007; Rosner et al., 2010).

The 2024 review by Hanauer et al. was meant to examine efficacy of psychosocial interventions for both prevention and treatment of grief in bereaved children/adolescents, with secondary outcomes of PTSD and depression, in a total of 39 controlled and uncontrolled studies (27 preventive and 12 treatment) (Hanauer et al., 2024). Uncontrolled preventive studies showed significant effect size for grief from pre- to post-intervention until adjusted for publication bias, which reduced the positive effect, leading to a nonsignificant result (Hanauer et al., 2024). Controlled preventive studies showed a significant but small effect size for grief from pre- to post-intervention (Hanauer et al., 2024). Uncontrolled treatment studies yielded a large effect size on grief at post-intervention; a pooled effect size for controlled treatment studies could not be calculated due to low number of studies reporting post-intervention effects, although the individual studies suggest a positive trend (Hanauer et al., 2024). Pooled follow-up effect sizes for preventive and treatment studies could not be calculated due to low number of studies reporting follow-up effects (Hanauer et al., 2024). Due to the small number of studies, moderator analyses could not be performed to provide insight into what influenced reported effect sizes (Hanauer et al., 2024). Similar to previous meta-analyses, Hanauer and colleagues found that treatments targeting those with higher symptom levels were more efficacious (Hanauer et al., 2024). Overall, the authors conclude that, although there is limited evidence, psychosocial interventions likely do clinically improve grief symptoms in bereaved children and adolescents, although studies of higher methodological quality are needed to draw stronger, and more specific, conclusions (Hanauer et al., 2024).

In the 2024 review by Saladino and colleagues focusing on CBT interventions in pediatric populations, they found a total of 20 studies that displayed clinically significant improvements (medium to large effect sizes) in PGD symptoms and global functioning post-intervention (Saladino et al., 2024). The authors concluded that CBT is effective for PGD in the pediatric population, although they noted study heterogeneity and variable quality due to bias in some included studies, calling for validation of their findings with further research (Saladino et al., 2024). Overall, there is some data to support the use of psychosocial interventions, particularly CBT, in pediatric populations, but more high-quality studies need to be performed to solidify these findings, especially given that PGD in pediatric populations has not been explored as much as in adults.

COMMUNITIES OF COLOR

Most studies in the last few decades on PGD in adult populations have primarily looked at higher educated female adults from Western countries, often not specifying race or ethnicity (Wittouck et al., 2011). A meta-analysis of grief-focused CBT for PGD similarly demonstrates this pattern, with their findings showing 86% of the total participants as female, and race or ethnicity of participants not being included in their analyses (Komischke-Konnerup et al., 2024). One notable exception to this pattern is one of the first RCTs, in which the authors recruited from both a university-based psychiatric research clinic, with predominantly White and higher socioeconomic status recruits, as well as a satellite clinic in a low-socioeconomic status Black community in the early 2000s (Shear et al., 2005). Even in this study, participants followed the trend of being mostly women (Shear et al., 2005). No differences in response rate or outcomes to the intervention were found based on race (Shear et al., 2005).

Interestingly, studies in bereaved pediatric populations have been more diverse; although many studies still come from Western nations, they include non-White patient samples (Hanauer et al., 2024; Saladino et al., 2024). In one study of grief interventions in children, the sample was 100% composed of African American children and found that two grief- and trauma-focused CB-based therapies improved traumatic grief symptoms post-intervention and at follow-up (Salloum & Overstreet, 2012). Compared to the studies performed in adults, the data on grief interventions among non-White groups is stronger in studies performed in children. Data suggests that race and ethnicity do not moderate treatment effect sizes observed in meta-analysis, supporting the conclusion that grief-based CBT is effective for young people of all races and ethnicities (Saladino et al., 2024). A key weakness in multiple recent reviews of psychotherapy interventions for grief in adult populations is a lack of discussion on ethnicity or race in the patient populations included (Johannsen et al., 2019; Komischke-Konnerup et al., 2024). Further, in the most recent review of CBT for PGD, they do note a limitation of the study is that most of the studies they included were from Western regions, which limits the generalizability of their findings globally, and potentially even in more diverse nations (many of their included studies were conducted in less diverse European nations) (Komischke-Konnerup et al., 2024). Based on the limited data available on grief psychotherapy interventions in populations of color, race, and ethnicity do not appear to limit the efficacy of the interventions, although more research needs to be done that specifically focuses on assessing if ethnicity or race is a moderator of the effect sizes reported.

UNDERSERVED COMMUNITIES

Current ideas about diagnosing PGD are centered around determining what is typical grief and what is pathological grief. These ideas are likely affected by cultural norms and values. Many cultures have different ideas about what the mourning process/-grief process should look like, as grief is a universal human experience. Unfortunately, most measures to assess PGD symptoms and diagnose PGD were developed in U.S. and their validity outside of the U.S. has been established in some studies (Aliyaki et al., 2024; Bryant et al., 2024; Haider & Zaman, 2024; Sveen et al., 2020), but clearly more work is needed in this area (Hilberdink et al., 2023). Despite this, it is thought that some populations across the globe are at higher risk for PGD, such as refugees, migrants, and conflict survivors, and these groups have been found to have higher incidence of disordered grief reactions (Hilberdink et al., 2023; Killikelly et al., 2018). However, it is unclear the extent to which these data are influenced by concerns related to measurement validity. Indeed, Hilderdink et al. call for more transcultural research to better understand cultural differences in PGD and how treatment can best be adapted across cultures (Hilberdink et al., 2023). They also call for more cost- and time-efficient treatments for PGD, as the current models for treatment are long and need to be provided by trained therapists, a limited resource globally (Hilberdink et al., 2023).

In considering underserved groups as defined as low socioeconomic status with minimal access to resources, one study of children in both rural and urban Kenya and Tanzania found that trauma-focused CBT for bereaved children was superior to usual care for grief symptoms in most contexts (Dorsey et al., 2020). Usual care mostly consisted of education-related services (tuition/school fees, uniforms, with only a small group receiving mental health services) (Dorsey et al., 2020). A majority of the Kenyan children (both rural and urban) reported going to bed hungry in the last 14 days “some or all of the time” and were also more likely to have “fair or poor” health compared to their Tanzanian counterparts, suggesting they were comparatively “underserved” (Dorsey et al., 2020). Interestingly, trauma-focused CBT was found to be more effective for grief symptoms in the Kenyan populations (who had higher levels of stress and adversity), with effect sizes reaching significance for 3 out of 4 sites (rural and urban Kenya, urban Tanzania) at posttreatment and for 2 out of 4 sites (rural and urban Kenya) at 12-month follow-up (Dorsey et al., 2020). These findings suggest that grief-focused CBT may even be more effective in lower-resourced or underserved areas (with higher levels of adversity) than in higher-resourced areas (where most of the studies on grief therapies have been performed). Although these are promising results which suggest that underserved communities may benefit more from current psychotherapeutic grief treatments, more research needs to be conducted to draw more generalizable conclusions on this topic.

Conclusions

Given the available evidence, grief-focused CBT-based therapies currently have the strongest evidence supporting their use in PGD, although there is significant heterogeneity and bias among existing studies. More RCTs need to be performed to optimize this type of therapy for PGD patient populations to figure out the most efficient and efficacious ways to help those suffering from PGD. In a world becoming increasingly connected by the internet, it is important to note that web-based therapies do not appear to be less effective than in-person therapies. Bereavement/support groups, which have long been used widely in those mourning a loved one and may be beneficial for cultivating social support for those with normative grief trajectories, have limited support demonstrating their clinical efficacy in treating PGD. Brief contact interventions, which are flexible, extremely brief, and easily disseminated, have promise for PGD but the data is similarly lacking in supporting their efficacy.

In terms of addressing specific clinical populations, some studies show promise in those bereaved by traumatic events, but recent systematic reviews suggest variable results and call for more research into these high-risk populations to find better approaches to PGD in these groups. Children seem to benefit from psychosocial interventions for PGD, similar to adults, with the strongest evidence suggesting that grief-focused CBT-based therapies are superior; however, study quality and high heterogeneity may limit the clinical applicability of the current evidence. Regarding race and ethnicity, the limited evidence available suggests that some communities of color (e.g., Black and African American populations) benefit similarly from the existing treatments compared to White patient populations. However, reporting race and ethnicity in studies of grief therapy needs to become more ubiquitous, and research examining the efficacy of these interventions within racially and ethnically diverse populations is needed. Notably, although there is limited evidence on grief psychotherapies in underserved populations, low socioeconomic status groups with minimal access to resource may benefit the same or even more from existing treatments in terms of PGD symptom improvement. This is an important finding, as these groups tend to face greater adversity and may experience PGD at higher rates.

A common conclusion across review studies on grief interventions is the lack of strong data to support any intervention over another (Dias et al., 2019), coming from inconsistency in the measurement of grief symptoms and the ability to diagnose PGD. There remain key controversies in the diagnosis of PGD, even with the addition of PGD to the DSM-5-TR and ICD-11. However, it is becoming more commonplace to assess for PGD in studies on grief (Komischke-Konnerup et al., 2024), but these ongoing controversies make it challenging to draw strong conclusions in larger studies like meta-analyses. We need a consensus on how to measure grief so that, across studies, we can draw stronger conclusions about what interventions are efficacious, as well as to stratify grief severity to understand what helps sicker patients more. In a recent commentary, our group concludes that the PG-13-R should be this tool, as it can be used to assess grief severity, for diagnosis, and has been validated cross-culturally (Prigerson & Maciejewski, 2024).

For future studies on psychotherapeutic interventions for PGD, it will be important for researchers to include a clear rationale for the chosen grief scale used to quantify grief symptoms. Researchers must also be thoughtful to select patients from diverse populations, both in terms of race and ethnicity but also socioeconomic status. Additionally, work needs to be done to modify and improve the existing treatments with the strongest evidence, like grief-focused CBT, to allow them to help even more people suffering from PGD. More work needs to be done to elucidate if tailoring the grief therapy to the type of loss (i.e., natural versus unnatural) will improve outcomes for those suffering, as well as exploring whether targeted preventive interventions for bereaved people can prevent the development of PGD all together.