Preliminary Findings for Group Transdiagnostic Behavior Therapy for Affective Disorders Among Youths

Transdiagnostic treatments are designed to incorporate components of various overlapping disorder-specific evidence-based psychotherapy protocols into a single, unified treatment for a set of specific diagnoses (1). Transdiagnostic treatments have been developed for several groups of diagnoses, with an initial focus on eating disorders and subsequent expansion to depressive, anxiety, obsessive-compulsive, and trauma-related disorders. Although much of the progress to date in treating affective disorders with transdiagnostic psychotherapies has occurred with adults (2), there has been recent encouragement to develop these therapies for youth samples and to investigate their efficacy among youths (3, 4). Although initial symptom outcomes are similar for disorder-specific and transdiagnostic protocols, transdiagnostic approaches may provide benefits in terms of dissemination and implementation as well as in addressing comorbid symptomatology (1, 2).

Initial studies in youth samples have been completed for certain transdiagnostic protocols, including group behavioral activation therapy (GBAT) (5) and the unified protocol for the treatment of emotional disorders among adolescents (UP–A) (6). GBAT was adapted from the literature on treatment of adults, with a situational exposure component added to address depressive as well as anxiety symptoms. In a study of school-aged youths (ages 12–14) (5), GBAT outperformed a waitlist control condition, as measured by diagnostic remission rates and overall impairment, but failed to demonstrate reliably improved symptom outcomes. Similarly, UP–A is an individual psychotherapy that was adapted from the literature on treatment of adults as a flexible protocol that includes five primary and three supplemental modules. In a study of adolescents (ages 12–17) with anxiety disorders, UP–A outperformed a waitlist control condition on all symptom outcome measures posttreatment. Given the potential limitations of these treatments (e.g., lack of improvement in symptom outcomes for GBAT compared with the waitlist condition and the requirement of individual delivery for UP–A), additional transdiagnostic protocols, especially group-based protocols, should be investigated.

Another transdiagnostic protocol from the adult literature, transdiagnostic behavior therapy (TBT), may offer promise for treatment of affective disorders among youths (7). TBT was developed as a streamlined protocol to facilitate education, preparation, practice, and mastery of four types of exposure techniques (situational, interoceptive, imaginal, and positive emotional) to reduce transdiagnostic avoidance and consequent impairment (7). The strength of the protocol lies in its behavioral format and in its demonstrated outcomes across a wide range of diagnoses (8), effectiveness as a group intervention (9), and ease of dissemination to community providers (10). However, the efficacy of TBT only has been investigated in adult samples, limiting its generalizability to other age groups.

The goal of this study was to complete a preliminary investigation of group TBT in a diagnostically diverse youth sample (ages 16–19) to determine its feasibility and efficacy. This initial investigation will be used to inform the merit of completing randomized controlled trials of group TBT in this population in the future. We hypothesized that group TBT would show pre- to posttreatment symptom improvements in primary symptomatology (anxiety), comorbid symptomatology (depression), and transdiagnostic impairment among youths.

Methods

Participants

Participant responses were collected from an outpatient sample at a specialized clinic for assessment and treatment of anxiety disorders in a Canadian hospital setting. Study inclusion criteria included meeting diagnostic criteria for a principal diagnosis of a DSM-5 anxiety disorder, depressive disorder, or posttraumatic stress disorder and being age 16–19. Data collection took place between July 2014 and May 2018 and was concluded due to its long duration, rather than because a specific recruitment target was reached.

Procedures

All procedures and measures used in this study were approved by the Hamilton Integrated Research Ethics Board at St. Joseph's Healthcare, Hamilton and McMaster University. At the intake appointment, participants provided full informed consent and completed the Diagnostic Assessment Research Tool (11) to establish principal and additional diagnoses for current and lifetime conditions and to establish inclusion criteria for the study treatment. Group TBT consisted of 12 weekly 120-minute manualized group psychotherapy sessions. Groups of six to eight participants were led by two or three clinicians with training in TBT. Clinicians were provided the TBT protocol, were trained by the protocol’s author, and had successfully completed a previous study on group TBT (9). Pre- and posttreatment self-report questionnaires were administered after sessions 1 and 11, respectively. The questionnaire packet included the Depression Anxiety Stress Scales (DASS) (12) to assess symptoms of depression, anxiety, and stress; the Illness Intrusiveness Rating Scale (IIRS) to assess transdiagnostic impairment (13); and the State-Trait Inventory for Cognitive and Somatic Anxiety (STICSA) to assess symptoms of cognitive and somatic anxiety (14).

Group TBT

TBT was developed as a streamlined protocol to teach, prepare for, practice, and master four types of exposure techniques (situational, interoceptive, imaginal, and positive emotional) to reduce transdiagnostic avoidance and lead to symptom remission. We adapted the protocol for the adolescent sample by including a module on self-esteem, by moving the coping statements module earlier in treatment, and by implementing minor changes to the language to make the examples more relevant to adolescents. TBT has received initial support as an individual therapy (7, 8, 10) and as a slightly revised group format (9) in adult samples. The treatment includes psychoeducation on avoidance and related behavioral goal setting (sessions 1–2), psychoeducation and treatment rationale for transdiagnostic exposure (sessions 3–4), and practice and refinement of exposure practices (sessions 5–11). We tailored in-session exposure practices to individual participants or groups of participants (e.g., four participants traveled to a cafeteria for situational exposures; two participants remained in the room for interoceptive exposures). We included the optional modules on coping statements and safety behaviors to further encourage exposure practices in all groups and included other modules as requested by group members (e.g., sleep disruption). TBT concluded with a final session to review treatment progress and relapse prevention strategies (session 12). (A copy of the TBT manual is available upon request.)

Data Analysis

Data from the measures administered to all participants (demographic, diagnostic, and self-report measures) were inspected for missing values. Minimal missing data were identified across measures (e.g., no participant was missing >2% of total data; <2% of the total data was missing in the full sample). One participant was missing data from the entire IIRS scale. Given the limited missing data, no participants were excluded from the analyses for significant missing data. We used within-scale mean substitution to replace missing values for participants with minimal missing data, except for the missing IIRS scale for one participant. We used paired sample t tests to investigate overall treatment effects across the DASS scales (depression, anxiety, and stress) and the IIRS and STICSA scales (cognitive and somatic) across all participants. Because of procedural limitations, no data were available on those who did not complete the protocol.

Results

Demographic Characteristics­

All participants were ages 16–19 (mean±SD=17.6±0.8) and single (N=20, 100%). Most participants reported actively participating in their high school (N=12, 60%) or college (N=4, 20%) education. A majority of the sample was white (N=16, 80%). Participants endorsed symptoms consistent with principal diagnoses of panic disorder (N=10, 50%), generalized anxiety disorder (N=5, 25%), social anxiety disorder (N=4, 20%), or posttraumatic stress disorder (N=1, 5%). The most common comorbid diagnoses were major depressive disorder (N=13, 65%), panic disorder (N=5, 25%), and generalized anxiety disorder (N=4, 20%).

Group TBT Treatment Outcomes

Treatment outcomes, as measured by the DASS, STICSA, and IIRS, are presented in Table 1. Participants demonstrated significant improvements across all outcome measures for anxiety symptomatology, including DASS anxiety and STICSA cognitive and somatic anxiety (t>2.1, p<0.05 for all measures), with moderate effect sizes (Cohen’s d ranged from 0.48 to 0.79). Significant treatment improvement also was observed on the DASS stress scale (t=2.4, p=0.025, d=0.48). No reliable improvements were observed on DASS depression or the IIRS.

Discussion

This study investigated group TBT in a sample of youths with affective disorders. Prior to this investigation, TBT had been investigated only among adult samples. These findings support the effectiveness of group TBT for symptoms of anxiety and stress, with moderate effect sizes demonstrated. The findings for the efficacy of this therapy for depression and overall impairment, however, were small and unreliable. Together, these findings provide initial evidence for the effectiveness of TBT among youths with anxiety symptomatology.

The findings of weaker treatment effects of TBT for depressive symptoms and overall impairment were surprising. In previous studies of individual and group TBT (7–10), the treatment effects for depression and impairment have been consistently large. One possible explanation for the present findings may be the less severe symptoms evidenced at baseline in our youth sample. Compared with previous TBT studies (8), baseline depressive symptoms (35% weaker) and impairment (21% weaker) appeared to be less severe among the present sample. However, the measures of anxiety, including the DASS anxiety (9% weaker), STICSA cognitive (7% stronger), and STICSA somatic (5% stronger) scales, were more consistent with scores shown in previous studies. Given these findings, it is possible that our participants experienced less severe comorbid symptoms and related impairment compared with adult samples, thus limiting potential treatment gains in these areas. Relatedly, a meta-analysis of psychotherapies reported weaker effect sizes across youth compared with adult samples (15). It also is possible that this treatment was simply less effective for depressive symptoms in this population.

These findings suggest that group TBT may be an effective treatment for youths with anxiety disorders. Because of the noted benefits of TBT in the literature on treatment of adults, including the therapy’s ease of dissemination (10) and group format that may improve access and social reintegration (9), group TBT should be further tested with youth samples. Future investigations should address the limitations of the present design, such as by adding a comparison group (waitlist control or active control), increasing the sample size, recruiting participants with principal diagnoses of depressive disorders, tracking rates of premature discontinuation and patient satisfaction, recruiting participants with more severe baseline symptomatology, and completing fidelity checks on the delivery of the intervention.

Conclusions

The present study investigated a group TBT protocol among youths with various anxiety disorders. This study adds to the growing literature on TBT options for youths, providing clinicians with a third option, aside from GBAT and UP-A. Although additional research is needed on each of these protocols, the initially promising findings suggest that transdiagnostic interventions may be effective for youths, as has already been demonstrated in various groups of adults with affective disorders.