Child-Centered Play Therapy for Youths Who Have Experienced Trauma: a Systematic Literature Review

Abstract

This systematic review examines the literature on the effectiveness of child-centered play therapy (CCPT) for youths who have experienced traumatic events. Two independent reviewers conducted the search procedures, as well as all data extraction and coding. Seven peer-reviewed articles reporting treatment outcomes were included in the review. As the focus of the review was on CCPT, treatment methods were similar across the seven articles (e.g., use of similar materials). There was also some consistency in findings regarding outcomes related to internalizing problems, self-concept, and self-competence. However, there was significant variability in the outcome measures used to evaluate effects, as well as limitations regarding the study methods that impact the overall conclusions regarding the use of CCPT to treat children that have experienced traumatic events. Treatment recommendations and suggestions for future research are discussed.

Posttraumatic stress disorder (PTSD) is characterized by the development of characteristic symptoms following exposure to one or more traumatic events (e.g., threatened or actual physical assault, threatened or actual sexual assault, natural or human-made disasters, severe accidents). Symptoms associated with PTSD include intrusion symptoms associated with the traumatic event, avoidance of stimuli associated with the traumatic event, negative alterations in cognitions or mood associated with the traumatic event, and/or marked alterations in arousal reactivity associated with the traumatic event (American Psychiatric Association 2013).

Results from the National Comorbidity Study-Adolescent Supplement indicate that the lifetime prevalence of PTSD for children ages 13 to 18 years in the U.S. is 5.0%, with females having a higher prevalence than males (8.0% and 2.3%, respectively) (Merikangas et al. 2010). Twelve month and 30-day prevalence estimates are 3.9% and 1.6%, respectively (Kessler et al. 2012). There are no definitive studies on prevalence rates of PTSD in younger children. However, it is important to note that in the U.S., the youngest children are most vulnerable to maltreatment, which may represent traumatic events (U.S. Department of Health and Human Services 2018). PTSD is associated with significant comorbidity, and trauma and PTSD symptoms may influence long-term behavioral and emotional development (Nader and Fletcher 2014; Perfect et al. 2016). Thus, it is critical that children with PTSD receive effective treatment.

Trauma-focused therapies (i.e., those that specifically address the traumatic experience) have been recommended to treat PTSD (see American Academy of Child and Adolescent Psychiatry 2010). Among the trauma-focused therapies for children, trauma-focused cognitive behavior therapy has received the most empirical support and has been the subject of multiple systematic reviews and meta-analyses (e.g., Black et al. 2012; Cary and McMillen 2012; de Arrellano et al. 2014; Gutermann et al. 2016). Nonspecific or nondirective therapies (i.e., those that do not specifically address the traumatic experience) represent alternatives to trauma-focused therapies. Individuals in these types of therapies may not spontaneously mention or address their traumatic experience (Cohen et al. 2004). Rather, nondirective therapy refers to unstructured therapy that relies primarily on the interpersonal skills of the therapist in ways that encourage individuals to explore and express their experiences and emotions (Cuijpers et al. 2012). Nondirective therapy with children typically involves play, as play represents an effective method for children to explore and express their experiences (Ewing et al. 2014).

A survey of mental health providers of play therapy indicates that the majority use a child-centered approach in play therapy (Lambert et al. 2007). In child-centered play therapy (CCPT), therapists use a playroom with carefully selected toys. The toys utilized in play are used as a means to elicit communication of the child’s view of his or her experiences (Axline 1969; Ray et al. 2015). As summarized by Ray et al. (2015), during play the therapist may reflect the child’s feelings, reflect content, track behavior, facilitate decision-making, facilitate creativity, encourage the child, facilitate relationships, and set limits for the child. Although play is not directed or necessarily trauma focused, when CCPT is used to address experiences of trauma, it is posited that it allows children to relive the trauma experience in a safe environment, including allowing children to express and work through painful emotions and to relieve accompanying tensions (Reyes and Asbrand 2005; Scott et al. 2003).

Although CCPT may be a preferred approach within the larger modality of play therapy (Lambert et al. 2007), and although play therapy has been used for treating children who have experienced traumatic events, few published studies have examined the effectiveness of this approach with this population (Gutermann et al. 2016). Recent reviews of CCPT indicate overall moderate treatment effects (e.g., Lin and Bratton 2015; Ray et al. 2015), but criticism regarding the relative lack of research examining the effectiveness of CCPT in general (Phillips 2010) and for trauma and PTSD specifically (see Gutermann et al. 2016) has yet to be adequately addressed. Notably, this specific topic has not been subject to systematic reviews of the research literature. Thus, the present systematic literature review aims to highlight the existing research on CCPT for children who have experienced traumatic events.

Method

Search Procedures

Keyword Search and Inclusion Criteria

Two graduate students independently retrieved scholarly journal articles from multiple online databases, including PsycINFO, Psychology Database, PsycARTICLES, SocINDEX, Psychology and Behavioral Sciences Collection, ERIC (EBSCO), and PubMed. The Boolean phrases used were: (“play therapy” OR “child-centered play therapy” OR “child centered play therapy” OR “non-directive play therapy” OR “therapeutic play” OR “play intervention” OR “sandtray” OR “person-centered play therapy” OR “humanistic play therapy”) AND (child* OR adolescent) AND (“traumatic event” OR “trauma” OR “stressful event” OR “psychological trauma” OR “maltreatment” OR “psychological maltreatment” OR “stress” OR “acute stress” OR “abuse”). Databases were searched up to June 2017, with no set limit on the start date.

To be included in the review, studies had to meet the following inclusion criteria: (a) the majority of the participants were 17 years of age or younger; (b) the treatment protocol (i.e., intervention) was systematically manipulated by the research team; (c) the study included a quantitative analysis of treatment effects; (d) the participants must have experienced exposure to actual or threatened death, serious injury, or sexual violence in one (or more) ways (based on the American Psychiatric Association 2013 criteria for PTSD); and (e) the researchers specified that therapy utilized in the study was based on CCPT. Studies were excluded if they did not meet the criteria listed above, were not per-reviewed, were literature reviews, were meta-analyses, were published in a language other than English, made use of therapies not identified as CCPT, or were uncontrolled or qualitative case studies that included anecdotal or interview data rather than quantitative data.

With the inclusion and exclusion criteria outlined, each graduate student independently identified 785 articles. After eliminating articles found on multiple databases (i.e., duplications) and articles that were not peer-reviewed, the number of articles was reduced to 635. The interrater reliability of the keyword search was assessed using the “irr” package (Gamer et al. 2012) in R Version 3.3.2 (R Core Team 2013). Results indicated an unweighted Cohen’s kappa of 0.98, which can be characterized as “almost perfect” interrater reliability per Landis and Koch (1977).

Title and Abstract Inspection

Next, titles and abstracts of all articles identified from the keyword search were independently examined for relevance. Articles were screened against the inclusion and exclusion criteria stated above. The interrater reliability results of the titles and abstract search between the graduate students indicated an unweighted Cohen’s kappa of 0.951, which can be characterized as “almost perfect” interrater reliability (Landis and Koch 1977). Following a meeting with the research team on article disagreements, the number of articles retained for full-text review was 172.

Full-Text Inspection

Inclusion and exclusion criteria remained the same. For articles that were not available through the university library, inter-library loan was utilized. The interrater reliability of the full-text review between the graduate students indicated an unweighted Cohen’s kappa of 0.942, which can be characterized as “almost perfect” interrater reliability (Landis and Koch 1977). Following a meeting with the research team on article disagreement, the number of articles retained for data extraction was seven.

Extended Search Procedures

The titles and abstracts of the references for each of the seven remaining articles were analyzed against the same inclusion and exclusion criteria. Of the references reviewed, zero met the criteria to be included in the final review and data extraction of articles. The interrater reliability results for this extended search indicated an unweighted Cohen’s kappa of 1.0, which can be characterized as “perfect” interrater reliability (Landis and Koch 1977). See Fig. 1 for a summary of the search procedure.

Fig. 1.

Flowchart depicting search procedures

Data Extraction

For each study remaining after the extended search procedures were completed, data were extracted pertaining to the following broad categories: (a) description of treatment programs, (b) description of research method, and (c) description of treatment outcomes. Regarding the treatment programs, information pertaining to treatment duration, treatment delivery, and treatment aims was extracted. Regarding the research method, information regarding the subjects (including age, sex, and trauma experiences) and study design was extracted. Regarding treatment outcomes, information regarding the outcome measures, specific outcomes, and effects was extracted. This information was coded by two researchers. All disagreements were resolved via review and discussion with the research team, resulting in 100% agreement.

Results

Description of Treatment Programs

Duration and Delivery

The duration of treatment ranged from 12 days to 9 months. The number of individual sessions attended by children ranged from 10 to 36 sessions. In three of the studies, children attended one CCPT session per week; in four of the studies, children attended multiple sessions per week (with one study utilizing daily sessions over the course of 12 days). Most studies reported the typical length of each session; the range for reported session length was 30 to 50 min.

Treatment was delivered by various mental health professionals, including counselors (four studies), social workers (three studies), therapists (not further defined; three studies), and psychologists (one study). Most of the studies specifically indicated that the therapists had received some sort of training (e.g., coursework, practicum) in CCPT (Kot et al. 1998; Schottelkorb et al. 2012; Scott et al. 2003; Shen 2002; Tyndall-Lind et al. 2001). Notably, Schottelkorb et al. (2012), the most recently published article, indicated that therapists utilized a manual to implement CCPT.

Based on information provided, there was some overlap in materials used in the studies. Three of the studies noted that the play settings (including toys and materials) used in therapy were based on those suggested by Landreth (1991, 2002). Two studies provided a general description of the toys and materials used in therapy. Two studies referenced play settings, but did not specify the types of toys or materials that were used. Notably, concurrent family therapy was available in one of the studies (Reyes and Asbrand 2005), and one study used sibling groups (Tyndall-Lind et al. 2001).

Treatment Goals

The treatment aims in the studies reviewed varied but there was some overlap. The most common goals involved improvement in self-concept and reduction in internalizing symptoms (three studies). Other common goals involved reduction in behavior problems (two studies) and positive changes in trauma-related symptoms (two studies). Improvement in positive play behavior, reduction in coercive family behaviors, improvement in social competence, and improvement in life adjustment were also targeted in the various studies. See Table 1 for a summary of each article’s treatment aims and aspects of treatment delivery.

Table 1.

Descriptive information and components of treatment

Author	Duration of treatment	Treatment delivery	Treatment aims	Components / Materials
Kot et al. (1998)	2 weeks; 12 sessions; 45 min per session	Counselors	Improving self-concept; reducing behavior problems; improving positive play behavior	Child-Centered Play Therapy; play settings equipped with toys and materials recommended by Landreth (1991)
Nicol et al. (1988)	Focused Casework: 8 weeks; 3 times per week Play Therapy: 2–3 months; 10 sessions	Focused Casework: Social workers Play Therapy: Social workers, clinical psychologist	Reduce coercive family behaviors and promote positive family behaviors	Focused Casework: multidisciplinary team meeting about family problems; established strategies to promote positive parenting; observations done during meeting Child-Centered Play Therapy: took place at the clinic and in one case at the school; settings equipped with doll’s house, paint, sandtray, train set, sink, cooking utensils, games and puzzles, drawing materials, and books
Reyes and Asbrand (2005)	9 months; 50 min sessions once per week	Therapists, social workers, counselors	Positive change in sexual abuse trauma symptoms	Child-Centered Play Therapy; settings were equipped with a sandtray with miniature figurines, puppets, art supplies, clay, dolls, cribs, dollhouses with furniture and people, books, and a variety of board games; Additional co-occurring family therapy was available but not mandatory
Schottelkorb et al. (2012)	CCPT: 12 weeks; 30-min sessions twice per week; 6 additional 15-min parent sessions TF-CBT: 9 weeks; 30-min sessions once per week for parent and child	Therapists (graduate students); Interpreters used when necessary	Decrease PTSD symptoms in multicultural populations	Child-Centered Play Therapy: play settings equipped with toys and materials recommended by Landreth (2002) and additionally equipped with appropriate cultural dolls, instruments, play food, and other toys Trauma-Focused Cognitive-Behavioral Therapy
Scott et al. (2003)	10 sessions; once per week	Social worker; Therapists	Increase mood, self-concept, and social competence in sexually abused children	Child-Centered Play Therapy; videotaped and monitored by other trained play therapists
Shen (2002)	4 weeks; 10 sessions; 40-min sessions 2–3 times per week	School counselor that spoke Mandarin	Help with issues of anxiety, depression, and life adjustment	Child-Centered Group Play Therapy; each group had 3 children; rooms were fully furnished
Tyndall-Lind et al. (2001)	12 days; 12 45-min sessions	Counselors	Improve self-concept and reduce internalizing/ externalizing behaviors and overall behavior problems	Intensive Sibling Group Play Therapy; playroom was equipped with toys and materials recommended by Landreth (1991)

Description of Research

Samples

The number of participants in treatment groups across the studies ranged from 10 to 38 (mean = 23.4). There were more girls than boys in five of the six studies that reported this information. In the treatment groups, the age of children ranged from 0 years to 16 years. The mean age of children, based on the average of studies reporting mean age, was 7.3 years. Children and families in the studies were recruited from various settings. In three studies, children were referred from child and family protective service agencies. In two studies, children were recruited from women’s shelters. In one study each, children were recruited based on geographic proximity to a natural disaster, based on refugee status and previous diagnosis with PTSD, and based on referrals from non-specified community agencies. The type of traumatic event(s) experienced by participants varied considerably. Two studies each included children that had been exposed to parental (domestic) violence or had been sexually abused. Other types of traumatic experiences (included in one study each) were physical abuse, persistent coercive family relationships, exposure to war, and exposure to a natural disaster.

Study Designs

Each of the seven studies used a pre-post treatment design. Three of the studies also used a control group. Shen (2002) used random assignment of participants to treatment conditions. Tyndall-Lind et al. (2001) used a waitlist control group, but did not specify how children were assigned to each condition. Kot et al. (1998) used a no treatment control group that was assigned after the experimental group had completed treatment. Two of the studies utilized comparative treatments (i.e., CCPT was compared to another treatment). Nicol et al. (1988) compared a focused casework approach (based on social support and behavior modification principles) to a CCPT approach. Schottelkorb et al. (2012) used random assignment to compare trauma-focused cognitive behavioral therapy to CCPT. See Table 2 for a summary of the sample and research design characteristics.

Table 2.

Sample and design of research

Author	Participants	Age (years)	Description of children	Type of traumatic experience	Attrition for CCPT group	Study design
Kot et al. (1998)	Tx group: 11 F = 6; M = 5 Cx group: 11 F = 7; M = 4	Tx group: Mean = 6.9; Range = 4–10 Cx group: Mean = 5.9; Range = 4–9	Entered a domestic violence shelter with mother	100% witnessed parental dispute and parental physical abuse (not specified)	45.0%	Pre-Post; Cx group
Nicol et al. (1988)	38	Mean (SD) = 4.8 (3.35) Range = 0–14	Referred to NSPCC; 14 families were single-parent households; 11 families were divorced	100% experienced physical abuse, persistent coercive family relationships	44.7%	Pre-Post; Comparative treatments (Play therapy listed as Cx)
Reyes and Asbrand (2005)	18 F = 13; M = 5	Mean = 11.1 Range = 7.3–16.6	Referred to non-profit community from various child protective sources	100% had evidence of sexual abuse, 80% of these cases were substantiated when they entered treatment	58.1%	Pre-Post
Schottelkorb et al. (2012)	31 F = 14; M = 17	Mean (SD) = 9.16 (2.03) Range = 6–13	Refugee students with full or partial PTSD designation	>50% (majority) experienced exposure to war and combat in their home country	16.1%	Pre-Post; Comparative Treatments
Scott et al. (2003)	26 F = 19; M = 7	Mean = 5.6; Range = 3–9	Referred from Utah County Division of Child and Family Services and Children’s Justice Center	100% experienced sexual abuse (substantiated cases only)	0% (7.7% did not complete follow-up)	Pre-Post
Shen (2002)	30 F = 16; M = 14	10 third graders, 8 fourth graders, 8 fifth graders, 4 sixth graders Range = 8–12	Chinese children living in Taiwan	100% experienced a large earthquake	Not reported	Pre-Post; Cx group
Tyndall-Lind et al. (2001)	Tx group: 10 F = 6; M = 4 Cx group: 11 F = 7; M = 4	Tx group: Mean = 6.2; Range = 4–9 Cx group: Mean = 5.9; Range = 4–9	Recruited from battered women’s shelters; Siblings were no more than 3 years of age apart	100% witnessed domestic violence	50%	Pre-Post; Cx group

Tx treatment, Cx control or comparison, F female, M male, Pre pre-treatment assessment, Post post-treatment assessment

Treatment Outcomes

Overall, the results across studies suggested that participation in CCPT led to improvements in self-concept and competence (four studies), internalizing problems (three studies), externalizing problems (two studies), and post-traumatic stress-related problems (two studies). Notably, non-significant effects for CCPT were also found in the majority of studies for various outcomes. Table 3 summarizes the results of each study, including indication of the significant effects found.

Table 3.

Results of research

Author	Outcome Measures	Outcomes	Effect
Kot et al. (1998)	Joseph Preschool and Primary Self-Concept Scale (JPPSCS); Child Behavior Checklist (CBCL); Children’s Play Session Behavior Rating Scale (CPSBRS)	Self-Concept Global Index (JPPSCS); Externalizing Behavior Problems (CBCL); Internalizing Behavior Problems (CBCL); Total Behavior Problems (CBCL); Observation – Affection (CPSBRS); Observation – Contact (CPSBRS); Observation - Physical Proximity (CPSBRS); Observation – Self-Direction (CPSBRS); Observation – Aggression (CPSBRS); Observation – Mood (CPSBRS); Observation – Play Themes (CPSBRS); Observation – Food Nurturing Themes (CPSBRS)	+ Tx-Cx; + Pre-Post Tx + Tx-Cx; + Pre-Post Tx 0 Tx-Cx; 0 Pre-Post Tx + Tx-Cx; + Pre-Post Tx 0 Tx-Cx; 0 Pre-Post Tx 0 Tx-Cx; 0 Pre-Post Tx + Tx-Cx; + Pre-Post Tx 0 Tx-Cx; 0 Pre-Post Tx 0 Tx-Cx; 0 Pre-Post Tx 0 Tx-Cx; 0 Pre-Post Tx + Tx-Cx; + Pre-Post Tx 0 Tx-Cx; 0 Pre-Post Tx
Nicol et al. (1988)	Family Interaction Coding System (FICS)	Coercive Behaviors; Positive Behaviors	0 Tx-Cx; 0 Pre-Post Tx 0 Tx-Cx; − Pre-Post Cx (Fathers only)
Reyes and Asbrand (2005)	Trauma Symptom Checklist for Children (TSCC)	Anxiety; Depression; Anger; Post-Traumatic Stress; Dissociation; Overt Dissociation; Fantasy; Sexual Concern; Sexual Preoccupation; Sexual Distress	+ Pre-Post + Pre-Post 0 Pre-Post + Pre-Post 0 Pre-Post 0 Pre-Post 0 Pre-Post 0 Pre-Post 0 Pre-post 0 Pre-Post
Schottelkorb et al. (2012)	UCLA PTSD Index for DSM-IV; Parent Report of Posttraumatic Symptoms (PROPS)	PTSD designation (UCLA); PTSD severity (PROPS)	+ Pre-Post (Full PTSD); 0 Tx-Cx + Pre-Post (clinical score); 0 Tx-Cx
Scott et al. (2003)	Joseph Preschool and Primary Self-Concept Scale (JPPSCS); Behavior Assessment System for Children-Parent Rating Scale (BASC-PRS)	Competence (JPPSCS); Global Scores (JPPSCS); Behavioral Index (BASC-PRS); Total scores (BASC-PRS)	+ Pre-Post 0 Pre-Post 0 Pre-Post 0 Pre-Post
Shen (2002)	Filial Problem Checklist (FPC); Revised Children’s Manifest Anxiety Scale (RCMAS); Multiscore Depression Inventory for Children (MDI-C)	Total score (FPC); Total score (RCMAS); Physiological anxiety (RCMAS); Worry/Oversensitivity (RCMAS); Social Concerns/Concentration (RCMAS); Lie factor (RCMAS); Total score (MDI-C); Anxiety (MDI-C); Self-esteem (MDI-C); Sad mood (MDI-C); Instrumental helplessness (MDI-C); Social introversion (MDI-C); Low energy (MDI-C); Pessimism (MDI-C); Defiance (MDI-C); Suicide Risk (MDI-C); Infrequency score (MDI-C)	0 Tx-Cx; + Pre-Post Tx + Tx-Cx; + Pre-Post Tx + Tx-Cx; + Pre-Post Tx + Tx-Cx; + Pre-Post Tx 0 Tx-Cx; + Pre-Post Tx 0 Tx-Cx 0 Tx-Cx; + Pre-Post Tx 0 Tx-Cx; + Pre-Post Tx 0 Tx-Cx; + Pre-Post Tx 0 Tx-Cx; + Pre-Post Tx 0 Tx-Cx; + Pre-Post Tx 0 Tx-Cx; 0 Pre-Post Tx 0 Tx-Cx; + Pre-Post Tx 0 Tx-Cx; + Pre-Post Tx 0 Tx-Cx; + Pre-Post Tx + Tx-Cx; + Pre-Post Tx 0 Tx-Cx
Tyndall-Lind et al. (2001)	Joseph Pre-School and Primary Self-Concept Scale (JPPSCS); Child Behavior Checklist (CBCL)	Global Score (JPPSCS); Total Behavior Problems (CBCL); Externalizing Behavior Problems (CBCL); Internalizing Behaviors (CBCL); Aggressive Behavior (CBCL); Anxious/Depressed (CBCL); Delinquent Behaviors (CBCL); Attention Problems (CBCL); Withdrawn Behavior (CBCL); Somatic Complaints (CBCL)	+ Tx-Cx; + Pre-Post Tx + Tx-Cx; + Pre-Post Tx + Tx-Cx; + Pre-Post Tx 0 Tx-Cx; 0 Pre-Post Tx + Tx-Cx; + Pre-Post Tx + Tx-Cx; + Pre-Post Tx 0 Tx-Cx; 0 Pre-Post Tx 0 Tx-Cx; 0 Pre-Post Tx 0 Tx-Cx; 0 Pre-Post Tx 0 Tx-Cx; 0 Pre-Post Tx

Tx treatment, Cx control or comparison, FU follow-up, Pre pre-treatment assessment, Post post-treatment assessment

+ = statistically significant positive change in outcomes between treatment-control or pre-post assessment; − = statistically significant negative change in outcomes between pre-post assessment; 0 = no statistically significant change

Kot et al. (1998), Tyndall-Lind et al. (2001), and Scott et al. (2003) reported significant differences between CCPT and control groups, as well as pre- and post-test differences in the CCPT group, for outcomes related to self-concept and competence. Results indicate that children who had witnessed parent (domestic) violence (Kot et al. 1998; Tyndall-Lind et al. 2001) and had experienced sexual abuse (Scott et al. 2003) felt empowered after receiving CCPT treatment. Relatedly, Shen (2002) reported significant pre- and post-test differences on a measure of life adjustment for children receiving CCPT after a natural disaster; however, there were no significant differences on this scale between the CCPT and no treatment control groups.

Reyes and Asbrand (2005) and Shen (2002) reported significant pre- and post-test differences in the CCPT group for outcomes related to internalizing problems. Tyndall-Lind et al. (2001) reported significant differences between CCPT and control groups, as well as pre- and post-test differences in the CCPT group, for depression and anxiety. Overall, results indicated that children who had a history of sexual abuse (Reyes and Asbrand 2005), had experienced a natural disaster (Shen 2002), and had witnessed parent (domestic) violence reported fewer symptoms of anxiety and depression after receiving CCPT. However, Kot et al. (1998) found no significant differences (including pre-post difference for the CCPT, and between the CCPT and control group) for internalizing problems in children who had witnessed parental (domestic) abuse. In addition, results regarding comparisons of the CCPT and control groups in Shen (2002) were mixed, with one measure (Revised Children’s Manifest Anxiety Scale) indicating that CCPT was superior to no treatment, and another measure (Multiscore Depression Inventory for Children) indicating that CCPT was not superior to no treatment.

Kot et al. (1998) and Tyndall-Lind et al. (2001) reported significant differences between the CCPT and control groups, as well as pre- and post-test differences in the CCPT group, for outcomes related to externalizing problems. This was based on reports of behavior of children who had a history of witnessing parental (domestic) abuse. Shen (2002) specifically reported significant pre- and post-test differences on a scale of defiance for children who had experienced a natural disaster, with children receiving CCPT reporting fewer related problems. However, Tyndall-Lind et al. (2001) did not report improvements for specific problems such as delinquent behaviors or attention problems.

In terms of post-traumatic stress-related problems, Reyes and Asbrand (2005) reported significant pre- and post-test differences in the CCPT group. Results indicated that children who had a history of sexual abuse and received CCPT reported fewer symptoms of overall post-traumatic stress. However, no pre- and post-test differences were found for specific difficulties sometimes associated with PTSD (e.g., dissociation, fantasy, sexual distress). Schottelkorb et al. (2012) also found significant pre- and post-test differences regarding overall post-traumatic stress; this was true for both parent- and self-reports for children who had been exposed to war. However, there were no significant differences when comparing CCPT to trauma-focused cognitive behavior therapy.

Notably, Nicol et al. (1988) reported no significant pre- and post-test differences in the CCPT group regarding coercive behaviors for children who had been physically abused and that had experienced coercive family relationships. Significance was found for positive behaviors; however, pre- and post-test scores indicated that fathers engaged in less positive behaviors after CCPT. In addition, the comparative treatment (based on social support and behavior modification principles) was found to be superior to CCPT.

Few studies examined any moderating effects or ways in which treatment differed based on participant characteristics. Nicol et al. (1988) reported results based on participant status (i.e., mother, father, or child) and Reyes and Asbrand (2005) evaluated the effects of factors related to the trauma (e.g., severity of abuse, duration of abuse), but the majority of studies did not evaluate the effects of participant characteristics. Also lacking from the statistical analyses of the majority of studies were analyses of effect size. It is becoming standard to report information on the amount of between-group differences (i.e., effect size) in addition to results of statistical significance testing. Shen (2002) and Reyes and Asbrand (2005) reported partial eta squared, and Schottelkorb et al. (2012) reported eta squared, but effect sizes were not reported in the other studies. Ranges of effect sizes were as follows: Shen (2002) = .019 to .274; Reyes and Asbrand (2005) = .33 to .43; Schottelkorb et al. (2012) = .43 to .57.

Discussion

Given the prevalence and wide-ranging effects of traumatic experiences and PTSD during childhood, mental health professionals clearly need evidence-based treatments (Nader and Fletcher 2014; Perfect et al. 2016). Although CCPT appears to be a popular treatment approach, there have been relatively few studies regarding its effectiveness on treating children exposed to traumatic events, and there is no overall consensus regarding its utility with this population (Gutermann et al. 2016). Thus, in this systematic review we examined the available research on the effectiveness of CCPT for children who have had traumatic experiences as defined by the American Psychiatric Association (2013). Only seven studies ultimately met criteria for inclusion in this review; these studies were published between 1988 and 2012. Overall, there was some consistency, but not complete uniformity, in the materials (e.g., toys) used in CCPT. There was also some consistency in findings regarding outcomes related to internalizing problems, self-concept, and self-competence. However, there was significant variability in the outcome measures used to evaluate effects, as well as limitations regarding the study methods that impact the overall conclusions regarding the use of CCPT to treat children that have experienced traumatic events.

Treatment Considerations

Based on the characteristics and components of the treatments described in Table 1, CCPT has been implemented in many diverse ways across different studies. All of the studies are based on CCPT, and there is some consistency in materials and treatment method. At the same time, most studies did not describe specific components of the treatment and only one (Schottelkorb et al. 2012) indicated that therapists used a manual to structure treatment delivery. Similarly, with the exception of Schottelkorb et al. (2012), the studies did not seem to report methods to assess treatment fidelity, and generally did not report if participants engaged in trauma-focused play (vs play that did not refer to the traumatic event).

We observed a wide range in treatment duration, which could have an impact on outcomes. For example, a child participating in daily therapy sessions for 12 consecutive days might have a very different experience and outcome compared to a child participating in weekly sessions for 9 months. Of course, this variability in implementation will be an issue when using an unstructured treatment approach. Interestingly, some studies focused on outcome variables other than, or in addition to, PTSD symptoms, such as self-concept, social competence, and behavior problems. It is possible that larger treatment effects may have been found if dependent variables were limited to the PTSD symptoms targeted by treatment. Overall, the existing research does not provide specific implications for play therapy for various types of trauma.

Research Considerations

Unfortunately, many articles identified in the initial search were excluded because they were uncontrolled case studies and/or did not present quantitative data analysis. Since only a few articles were left after the article search and selection process, we do not have an established “critical mass” of literature to allow us to make a general statement about effectiveness of CCPT with this population. We can, however, describe some of the characteristics of the studies included in this review. One characteristic that must be noted is the high attrition rate observed across studies (several in the 40–50% range). Treatment outcomes might have been more positive if more participants had actually completed treatment or attended more sessions. Perhaps the high attrition rates were related to the nature of the samples (i.e., youths who had experienced traumatic events) and treatment (i.e., treatment for traumatic experiences, which may have exacerbated feelings of distress or discomfort).

Another notable finding is the wide variety of dependent variables, or outcome variables, and a commensurate variety in how these variables were measured in the different studies. This lack of consistency, both in constructs measured and in how they were measured, may partially explain the inconsistent results across studies. That is, some studies found positive outcomes both when compared to a control group and when compared to pre-treatment functioning, but other studies (or other dependent variables within the same study) did not find significant differences or treatment effects. Further, some results suggest positive outcomes when comparing pre- to post-test data, but not when comparing outcome scores between treatment and control/comparison groups. There also was quite a variety in the samples used in the seven studies, with some studies including youth who had experienced natural disasters (i.e., an earthquake), others with children who had witnessed violence or war, and others with youth who had experienced physical or sexual abuse. Unfortunately, these inconsistencies prevent us from identifying patterns in the research or exploring whether CCPT may be more effective for some types of trauma than others. Only three of the seven studies reported effect sizes (either eta squared or partial eta squared), and those effect sizes were generally in the moderate to large range. This certainly provides preliminary support for the potential effectiveness of CCPT, and points to the importance and merit of further research in this area.

Limitations of Present Review

The current findings highlight important considerations for CCPT for youths that have experienced traumatic events, but the results must be interpreted in light of the review’s limitations. One limitation is the methodological rigor of our inclusion and exclusion criteria. In particular, we chose to exclude studies that did not include a quantitative data analysis of treatment effects. Although we did this to focus on articles that used more rigorous methodology and analyses, a consequence was that it significantly limited the number of articles we reviewed. Although other articles may have used less rigorous methods (e.g., uncontrolled case studies, narrative descriptions of the treatment process and outcomes), it may nonetheless be beneficial to glean evidence from these studies, especially given the relatively few studies of CCPT for trauma that utilize more rigorous methods. In addition, the majority of studies did not report effect sizes. This limited the ability to conduct additional evaluation of overall treatment outcomes, such as meta-analyses of outcome data and the potential impact of moderator variables on treatment outcomes. Although this reflects a limitation of the existing research, it nonetheless constrained our ability to further evaluate the data.

Conclusion

The seven identified studies included samples who experienced a range of traumatic events, used a variety of outcome measures, and found inconsistent pre-post and between-group differences. Perhaps the most striking conclusion to be drawn from this systematic review is the fact that, despite the popularity of CCPT approaches, there is very little research to support this popularity, at least when considering studies using a sufficiently rigorous design with youths who have experienced trauma. Even though we cannot make firm recommendations or conclusions regarding the effectiveness of CCPT, we can make several recommendations for future research in this area. First, researchers should explore ways to reduce attrition rates in these studies (and, most likely, in these treatment programs more generally). That is, how can we encourage participants to remain in treatment and help them work through initial feelings of distress that may accompany re-experiencing or processing traumatic events? Second, researchers might consider identifying and using common outcome measures so that results can be more easily compared across studies. Third, more rigorous research designs must be used to enable the field to establish stronger evidence for the effectiveness of CCPT with this population. Uncontrolled case studies may be helpful in the initial stages of developing and describing treatment approaches, but more rigorous designs are necessary to more precisely identify what treatments work best, for whom, and under what conditions.

In terms of methodology, in many ways the Schottelkorb et al. (2012) study should be viewed as an exemplar that future research studies on CCPT should follow, as those researchers used a comparison group, randomization, well-developed instruments, treatment manuals, and a treatment fidelity checklist. Fourth, researchers should routinely report effect sizes as part of their data analyses. Cohen’s d may be most appropriate when comparing outcomes for treatment group vs. control group, but any measure of effect size is better than nothing. Reporting effect sizes would also facilitate the application of meta-analytic techniques to quantitatively examine trends in effectiveness across studies. Lastly, we encourage researchers to describe play materials and content/components of sessions more thoroughly and operationally, so practitioners and other researchers will have a better understanding of what the treatment looked like. This is important for replication of results, and for practitioners who want to implement these treatments in their own practices.

Compliance with Ethical Standards

This study did not involve human participants.

Conflict of Interest

On behalf of all authors, the corresponding author states that there is no conflict of interest.