Differential relations between breathing retraining, in vivo exposure, and imaginal exposure homework completion and treatment outcomes in veterans receiving prolonged exposure for PTSD.

OBJECTIVES: Limited research exists that outlines the predictive relevance of the treatment components of prolonged exposure (PE) for post-traumatic stress disorder (PTSD) on PTSD and depression symptom outcomes. The goal of the present study was to investigate relations between participant completion of breathing retraining, in vivo exposure, and imaginal exposure exercises and symptom outcomes. METHODS: A total of 58 participants completed a trial of PE as part of a larger trial on peer involvement and treatment adherence. Diagnostic and self-report measures were completed throughout treatment. Participants also recorded weekly completion of breathing retraining, in vivo exposure, and imaginal exposure exercises. Pearson correlations and hierarchical regression analyses were used to investigate relations between average weekly treatment component completion and treatment outcomes, controlling for relevant variables. RESULTS: Although breathing retraining and in vivo exposures were associated with PTSD outcomes in the correlational findings, use of breathing retraining, in vivo exposures, and imaginal exposures were not reliably associated with PTSD symptom outcomes when controlling for other variables in the regression analysis. However, when investigating changes in comorbid symptoms of depression, greater use of breathing retraining was associated with decreased symptoms of depression at posttreatment. CONCLUSIONS: Present findings demonstrate the differential relations between participation in various PE treatment components and posttreatment symptom outcomes. The importance of breathing retraining in addressing comorbid depressive symptoms is discussed, with emphasis on potentially increasing relaxation and positive activities more broadly to encourage further treatment benefits.

Exploring trajectories in transdiagnostic behavior therapy.

Transdiagnostic treatments have been designed to target common processes for clusters of disorders. One such treatment, transdiagnostic behavior therapy (TBT), targets avoidance across emotional disorders, including posttraumatic stress disorder (PTSD), depressive disorders, and anxiety disorders, and has demonstrated efficacy in randomized controlled trials. The current study was designed to examine whether distinct treatment trajectories would emerge in a sample of 112 veterans receiving TBT and whether diagnostic comorbidity, baseline levels of several transdiagnostic risk factors, or treatment engagement influence trajectory membership. Growth mixture modeling revealed three distinct trajectories across depression, ds = 0.55-1.09; PTSD ds = -0.07-1.43; and panic disorder symptoms, ds = -0.13-1.09. Notably, for PTSD and panic disorder symptoms, separate classes for responders and nonresponders emerged among participants with high baseline symptom levels. Findings for the risk factors suggested that PTSD and panic nonresponders evidenced significantly higher behavioral avoidance at baseline and reduced engagement in treatment procedures and homework completion compared to responders. Together, the findings provide additional support for the use of TBT in the treatment of emotional disorders, including PTSD. Potential adaptations are discussed for patients with significantly elevated behavioral avoidance to improve treatment engagement and related outcomes.

Anxiety sensitivity and social support in veterans with emotional disorders.

OBJECTIVE: An understanding of the incremental value of social support in predicting psychopathology above transdiagnostic risk factors could speak to the benefit of leveraging social factors into existing, evidence-based interventions in veterans with emotional disorders. This cross-sectional study aimed to expand our understanding of associations between domains of anxiety sensitivity and facets of psychopathology in veterans with emotional disorders. We also determined whether social support predicted psychopathology above anxiety sensitivity domains and combat exposure and explored these relationships with a path model. METHODS: One hundred and fifty-six treatment-seeking veterans with emotional disorders completed diagnostic interviews and assessments of demographics, social support, symptom measures (e.g., PTSD, depression, anxiety, and stress), and transdiagnostic risk factors (i.e., anxiety sensitivity). After data screening, 150 were included in regressions. RESULTS: Using regression analyses with cross-sectional data, cognitive anxiety sensitivity concerns predicted PTSD and depression above combat exposure. Cognitive and physical concerns predicted anxiety, and cognitive and social concerns predicted stress. Above combat exposure and anxiety sensitivity, social support predicted PTSD and depression. CONCLUSION: Focusing on social support in tandem with transdiagnostic mechanisms in clinical samples is critical. These findings inform transdiagnostic interventions and recommendations related to incorporation of assessment of transdiagnostic factors in clinical contexts.

Influence of comorbid social anxiety disorder in PTSD treatment outcomes for Prolonged Exposure in female military sexual trauma survivors with PTSD.

OBJECTIVE: Posttraumatic stress disorder (PTSD) is a common psychiatric disorder that frequently presents alongside other comorbid diagnoses. Although several evidence-based psychotherapies have been well-studied for PTSD, limited research has focused on the influence of diagnostic comorbidity on their outcomes. The present study sought to investigate the influence of comorbid social anxiety disorder on treatment outcomes in patients with PTSD. METHODS: One hundred and twelve treatment-seeking female veteran participants with PTSD completed baseline assessments and received 12-15 sessions of Prolonged Exposure. Symptom measures were completed biweekly as well as at immediate posttreatment, 3-month, and 6-month follow-ups. RESULTS: Thirty (26.8%) participants seeking PTSD treatment also met diagnostic criteria for social anxiety disorder. Multilevel modeling was used to examine effects of social anxiety disorder diagnosis on post-intervention symptoms and revealed significantly worse outcomes for symptoms of PTSD and depression in participants with comorbid PTSD and social anxiety disorder. CONCLUSION: Consistent with previous studies of co-occurring PTSD and depression, present findings suggest that comorbid diagnoses may adversely affect disorder-specific treatment outcomes. As such, the presence of diagnostic comorbidity may merit further consideration and potential adaptions to the traditional, disorder-specific assessment and treatment practices for PTSD.

Investigating Relations Between the Symptoms of Panic, Agoraphobia, and Suicidal Ideation: The Significance of Comorbid Depressive Symptoms in Veterans with Panic Disorder.

Although panic disorder has been frequently associated with increased suicidal ideation and behaviors, there are multiple explanations for this association in the literature. For example, some research has demonstrated panic disorder symptoms to mediate agoraphobia and suicidal ideation, while other researchers have hypothesized that comorbid depression symptoms contribute to suicidal ideation across anxiety disorders. Of note, none of these studies were completed in veterans, a population at higher risk for suicide relative to civilian samples. The present study investigated relations between the symptoms of panic, agoraphobia, depression, and suicidal ideation in 58 veterans diagnosed with panic disorder via correlations, hierarchical regression, and exploratory path analyses. Multiple models were investigated based on prior research. The final path model demonstrated that symptoms of panic disorder predicted agoraphobia symptoms, with agoraphobia predicting symptoms of depression. Symptoms of depression, then, predicted suicidal ideation. Discussion of the findings related to comorbid depressive symptoms highlight considerations for the assessment and treatment practices for panic disorder, with a particular focus on veterans receiving care within Veterans Affairs Healthcare System.

Comorbidity as a moderator of the differential efficacy of transdiagnostic behavior therapy and behavioral activation for affective disorders.

OBJECTIVE: Transdiagnostic psychotherapies have been proposed as an effective means for addressing the needs of patients with multiple, comorbid disorders. Yet, it remains unknown whether transdiagnostic approaches empirically outperform disorder-specific psychotherapies for patients with comorbid disorders. Thus, this study tested whether comorbidity moderated the efficacy of transdiagnostic behavior therapy (TBT) and behavioral activation (BA) for patients with various affective disorders. METHODS: Data derived from a randomized controlled trial in which 93 treatment-seeking veterans received 12 sessions of TBT (n = 46) or BA (n = 47). Baseline comorbidity was assessed with a diagnostic interview. Patients rated their symptoms and functioning throughout treatment, and therapists recorded premature treatment discontinuation. RESULTS: Multilevel models revealed significant interactive effects on changes in symptoms and functioning, but not on the posttreatment levels of these outcomes; whereas patients with more comorbidity experienced greater reductions in distress and symptom interference in TBT compared to BA, those with one disorder had better outcomes in BA. Similarly, whereas patients with more comorbidity were less likely to prematurely discontinue TBT compared to BA, those with one disorder were less likely to prematurely discontinue BA. CONCLUSIONS: The results lend empirical support to previously untested hypotheses for potential benefits of transdiagnostic psychotherapies.Trial registration: ClinicalTrials.gov identifier: NCT01947647.

Temporal dynamics of symptom change among veterans receiving an integrated treatment for posttraumatic stress disorder and substance use disorders.

The present study examined temporal patterns of symptom change during treatment for comorbid posttraumatic stress disorders (PTSD) and substance use disorders (SUDs). We hypothesized that PTSD symptom severity would predict subsequent-session substance use and that this association would be particularly strong among patients who received an integrated treatment versus SUD-only treatment. Participants were 81 United States military veterans with current PTSD and an SUD who were enrolled in a 12-week, randomized controlled trial examining the efficacy of an integrated treatment called Concurrent Treatment of PTSD and Substance Use Disorders Using Prolonged Exposure (COPE) compared with cognitive behavioral relapse prevention therapy (RP). Lagged multilevel models indicated that PTSD symptom improvement did not significantly predict the likelihood of next-session substance use (likelihood of use: B = 0.03, SE = 0.02, p = .141; percentage of days using B = -0.02, SE = 0.01, p = .172. Neither substance use, B = 1.53, SE = 1.79, p = .391, nor frequency of use, B = 0.26, SE = 0.50, p = .612, predicted next-session PTSD symptom severity in either treatment condition. Stronger associations between PTSD symptoms and next-session substance use were expected given the self-medication hypothesis. Additional research is needed to better understand the temporal dynamics of symptom change as well as the specific mediators and mechanisms underlying symptom change.

A comparison of transdiagnostic behavior therapy (TBT) and behavioral activation treatment for depression (BATD) in veterans with major depressive disorder.

OBJECTIVES: Although frequently discussed within the scope of transdiagnostic psychotherapy protocols, limited data are available on their efficacy in patients with a principal diagnosis of major depressive disorder. The present study attempted to address that gap in the literature through a randomized clinical trial comparing transdiagnostic behavior therapy (TBT) to behavioral activation treatment for depression (BATD). METHODS: Forty veterans with principal major depressive disorder were randomized into either 12 sessions of individual TBT or BATD, with symptom measures collected at baseline and posttreatment. Process variables for treatment engagement and completion also were recorded. RESULTS: Participants reported similar symptom improvements in depression, stress, anhedonia, and impairment across both treatments. Clinician-rated treatment improvements favored TBT. Participants in TBT also attended more appointments, canceled or missed fewer appointments, and completed the protocol at a higher rate than participants that received BATD. CONCLUSIONS: The present findings support TBT as an efficacious treatment for principal major depressive disorder, with potentially superior coverage of comorbid anxiety symptomatology and improved treatment adherence and completion compared to BATD. Pending replication in larger samples, TBT and other similar transdiagnostic psychotherapies should be considered for implementation across the anxiety and depressive disorders to simplify dissemination efforts for evidence-based psychotherapies and potentially improve coverage of comorbidity.

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

OBJECTIVE: The literature on transdiagnostic psychotherapy among youths is limited. Group transdiagnostic behavior therapy (TBT) has been shown to be effective for adults with affective disorders and may contain beneficial features for youths (e.g., behavioral focus, group format, ease of dissemination, and diversity of targeted diagnoses). This study aimed to investigate group TBT among youths in Canada to determine its feasibility and efficacy. METHODS: Twenty participants (ages 16-19) diagnosed as having a principal anxiety disorder completed 12 sessions of group TBT. Symptoms of anxiety, depression, and transdiagnostic impairment were assessed pre- and posttreatment. RESULTS: Participants demonstrated significant improvements on measures of anxiety (general, cognitive, and somatic) and stress, with moderate effect sizes. Findings for symptoms of depression and transdiagnostic impairment were unreliable, with small effect sizes. CONCLUSIONS: These findings provide preliminary support for the use of group TBT among youths with anxiety disorders. Future research should incorporate comparison groups and larger samples.

Treatment Goals and Alcohol Use Outcomes in Veterans With Comorbid Alcohol Dependence and Posttraumatic Stress Disorder.

BACKGROUND AND OBJECTIVES: Previous research demonstrates the utility of goals in attaining improved drinking outcomes. Considerably less is known about the association between substance use goals and outcomes among persons with comorbid substance use disorder (SUD) and posttraumatic stress disorder (PTSD). This secondary analysis examined the association between alcohol use outcomes and participants' treatment entry substance use goals to either abstain or reduce substance use in the context of treatment for comorbid SUD/PTSD. METHODS: Participants (N = 39) were treatment-seeking veterans with current alcohol dependence and PTSD. Participants completed self-report and clinician-rated measures of substance use and PTSD as part of a larger randomized controlled trial. RESULTS: Participants in both goal groups (abstain; reduce) achieved significant reductions in the likelihood of drinking and the likelihood of exceeding low-risk drinking levels. The primary analysis did not identify significant differences in outcome between goal groups; however, the exploratory analysis revealed that participants with reduced use goals were more likely to drink and more likely to exceed low-risk drinking levels. CONCLUSION AND SCIENTIFIC SIGNIFICANCE: The findings suggest a moderately strong association between substance use goal and drinking outcome in the current study. Although the findings did not unequivocally support abstinence as a superior treatment goal, they offer a preliminary indication that abstinence may be an overall lower-risk option. These findings expand consideration of the utility of substance use goals and suggest that clinicians should invite consideration of abstinence but may need not limit integrated treatment for SUD/PTSD based on strict adherence to abstinence, particularly if low-risk use goals are targeted. (Am J Addict 2021;30:131-137).

Acceptability of a transdiagnostic behavior therapy in veterans with affective disorders.

Transdiagnostic behavior therapy (TBT) has been found to lead to significant reductions in affective disorder symptoms. However, patient satisfaction and treatment fit for TBT have not been examined. Within a sample of veterans, the current study examined the acceptability of TBT in comparison to brief behavioral activation (BA) for depression. Results found individuals in the TBT condition (compared to BA) were more satisfied with therapy, F(1, 48) = 6.68, p = .013. In addition, they were more likely to say that they would recommend this treatment to a friend, F(1, 48) = 3.76, p = .058, and that the TBT treatment helped them more effectively deal with problems, F(1, 48) = 3.29, p = .076, although these effects were significant at trend level. Individuals in the TBT condition (compared to BA) completed significantly more homework, F(1, 65) = 4.95, p = .030, and were more engaged in their homework, F(1, 65) = 3.98, p = .050. These findings are the first of their kind and suggest high patient satisfaction and homework completion/participation in participants completing TBT. These results are promising and suggest the continued dissemination and implementation of transdiagnostic treatments. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Response-to-Treatment for Comorbid Post-Traumatic Stress and Substance Use Disorders: The Value of Combining Person- and Variable-Centered Approaches.

Optimizing treatment for co-occurring post-traumatic stress disorder and substance use disorder (PTSD+SUD) is critically important. Whereas treatments have been designed that target PTSD+SUD with some success, these treatments do not benefit all. Data-driven approaches that combine person- and variable-centered methods, such as parallel process latent class growth analysis (PP-LCGA) can be used to identify response-to-treatment trajectories across both PTSD symptoms and substance use. The current study employed PP-LCGA separately in two randomized clinical trials (study 1 n = 81, Mean age = 40.4 years, SD = 10.7; study 2 n = 59, Mean age = 44.7 years, SD = 9.4) to examine PTSD symptom response and percentage of days using substances across treatment trials comparing Concurrent Treatment of PTSD and SUD using Prolonged Exposure and Relapse Prevention. Results revealed four PTSD+SUD profiles for study one and three PTSD+SUD profiles for study two. For PTSD symptoms, response trajectories could be broadly classified into treatment responders and non-responders across both studies. For substance use, response trajectories could be broadly classified into declining, moderately stable, and abstaining profiles. When considering PTSD symptoms and substance use trajectories together, profiles emerged that would have been missed had these treatment outcomes been considered separately.

Does trauma-focused exposure therapy exacerbate symptoms among patients with comorbid PTSD and substance use disorders?

BACKGROUND: Although exposure-based therapy is a well-established, effective treatment for post-traumatic stress disorder (PTSD), some practitioners report reluctance to implement it due to concerns that it may exacerbate symptoms of PTSD and commonly comorbid disorders, such as substance use disorders (SUD). AIM: This study compared the exacerbation of psychological symptoms among participants with comorbid PTSD and SUD who received either SUD treatment alone or SUD treatment integrated with exposure therapy for PTSD. METHOD: Participants (N = 71) were treatment-seeking, military Veterans with comorbid PTSD and SUD who were randomized to 12 individual sessions of either (1) an integrated, exposure-based treatment (Concurrent Treatment of PTSD and Substance Use Disorders using Prolonged Exposure; COPE); or (2) a non-exposure-based, SUD-only treatment (Relapse Prevention; RP). We examined between-group differences in the frequency of statistically reliable exacerbations of PTSD, SUD and depression symptoms experienced during treatment. RESULTS: At each of the 12 sessions, symptom exacerbation was minimal and generally equally likely in either treatment group. However, an analysis of treatment completers suggests that RP participants experienced slightly more exacerbations of PTSD symptoms during the course of treatment. CONCLUSIONS: This study is the first to investigate symptom exacerbation throughout trauma-focused exposure therapy for individuals with comorbid PTSD and SUD. Results add to a growing literature which suggests that trauma-focused, exposure-based therapy does not increase the risk of symptom exacerbation relative to non-exposure-based therapy.

Efficacy of transdiagnostic behavior therapy on transdiagnostic avoidance in veterans with emotional disorders.

OBJECTIVE: To date, transdiagnostic treatments have primarily investigated treatment outcomes of general psychiatric symptomatology, rather than the specific transdiagnostic symptoms implicated in their protocols. The present study sought to address this significant gap in the literature by investigating the effect of transdiagnostic behavior therapy (TBT) on transdiagnostic avoidance. METHOD: Forty-four veterans diagnosed with various emotional disorders initiated TBT, and completed diagnostic and self-report measures at pre- and posttreatment. RESULTS: Participants demonstrated reliable treatment improvements in measures of situational, thought, and positive emotional avoidance, with moderate-to-large effect sizes, and in measures of physical/interoceptive avoidance with small-to-medium effect sizes. CONCLUSIONS: The findings support the hypothesized effect of TBT in self-report measures of four types of transdiagnostic avoidance in participants diagnosed with various emotional disorders. These findings contribute to the growing literature on the potential benefits of the transdiagnostic approaches to address symptomatology across diagnoses.

An Open Trial of Behavioral Activation in Veterans With Major Depressive Disorder or Posttraumatic Stress Disorder in Primary Care.

OBJECTIVE: Integrated behavioral health programs provide brief evaluations and interventions to patients with psychiatric symptoms in primary care. These programs seek to decrease stigma and improve access to mental health services. Several psychotherapeutic interventions are available to providers, each with its own strengths and weaknesses. One treatment with particular promise is behavioral activation treatment for depression (BATD) due to its potential clinical efficacy, transdiagnostic potential, and ease of dissemination and implementation in primary care settings. The objective of this study was to investigate the efficacy of BATD across 2 DSM-5 diagnoses: major depressive disorder (MDD) and posttraumatic stress disorder (PTSD). METHODS: Participants were recruited from October 2014 to December 2017. Thirty-one participants were referred from primary care and consented to receive a 12-session trial of BATD. Participants endorsed criteria consistent with a principal diagnosis of either MDD (n = 20) or PTSD (n = 11). Self-report measures were completed at baseline and immediately posttreatment to monitor treatment progress in symptoms of PTSD and MDD. RESULTS: Twelve of the 31 participants completed all 12 sessions of BATD, although over 70% completed at least 4 sessions. Participants demonstrated significant symptom improvement across symptoms of MDD and PTSD (all P < .004). No disorder group differences were evidenced for symptom reduction, treatment completion, or treatment satisfaction. CONCLUSIONS: The present study provides support for the efficacy of BATD for patients with MDD and PTSD. These findings may have implications for the dissemination and implementation efforts for psychotherapies in integrated primary care settings. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01947647.

Efficacy of Transdiagnostic Behavior Therapy Across the Affective Disorders.

This study supports the efficacy of transdiagnostic behavior therapy across various affective disorders, including depression and PTSD. These findings suggest a possible reduction in the number of treatment protocols providers need to learn in order to treat patients with affective disorders.

A randomized controlled trial comparing Transdiagnostic Behavior Therapy (TBT) and behavioral activation in veterans with affective disorders.

This randomized controlled trial (RCT) compared the efficacy of Transdiagnostic Behavior Therapy (TBT) to Behavioral Activation Treatment for Depression (BATD) in veterans diagnosed with affective disorders. TBT is a transdiagnostic psychotherapy designed to address depressive, anxiety, and post-traumatic stress disorder (PTSD) symptoms. Preliminary findings have been promising; however, no RCT has been completed to date. 105 treatment-seeking veterans were recruited and completed diagnostic and self-report measures, and then randomized into TBT or BATD treatment conditions for 12 weekly psychotherapy sessions. Assessment measures were re-administered at immediate post-treatment and 6-month follow-up. Of the 93 participants initiating treatment, 50 participants completed the full treatment protocol (TBT n = 29; BATD n = 21). No differences were observed in treatment completion across groups. Participants demonstrated significant treatment improvements across all assessments, including measures of depression, anxiety (general, cognitive, and somatic), stress, PTSD symptoms, and transdiagnostic impairment. Group differences with small effect sizes were observed in most of the studied measures, favoring TBT compared to BATD. Together, the findings support the growing literature on the efficacy of transdiagnostic psychotherapies, compared to disorder-specific treatments (DSTs). Related to the outcome findings, the benefits for transdiagnostic protocols in terms of symptom coverage, dissemination, and access were discussed.

Residual Insomnia and Nightmares Postintervention Symptom Reduction Among Veterans Receiving Treatment for Comorbid PTSD and Depressive Symptoms.

While evidence-based interventions can help the substantial number of veterans diagnosed with comorbid PTSD and depression, an emerging literature has identified sleep disturbances as predictors of treatment nonresponse. More specifically, predicting effects of residual insomnia and nightmares on postintervention PTSD and depressive symptoms among veterans with comorbid PTSD and depression has remained unclear. The present study used data from a clinical trial of Behavioral Activation and Therapeutic Exposure (BA-TE), a combined approach to address comorbid PTSD and depression, administered to veterans (N = 232) to evaluate whether residual insomnia and nightmare symptoms remained after treatment completion and, if so, whether these residual insomnia and nightmare symptoms were associated with higher levels of comorbid PTSD and depression at the end of treatment. Participants (ages 21 to 77 years old; 47.0% Black; 61.6% married) completed demographic questions, symptom assessments, and engagement-related surveys. Hierarchical multiple linear regression models demonstrated that residual insomnia was a significant predictor of PTSD and depression symptom reduction above and beyond the influence of demographic and engagement factors (e.g., therapy satisfaction). Consistent with previous research, greater residual insomnia symptoms were predictive of smaller treatment gains. Findings illustrate the potential significance of insomnia during the course of transdiagnostic treatment (e.g., PTSD and depression), leading to several important clinical assessment and treatment implications.

A Single Integrated Behavioral Health Appointment Improves Patients' Perceptions of Behavioral Health Treatment.

OBJECTIVE: To determine if a single behavioral health appointment in primary care would result in improvements in participants' perceptions of mental health treatment. METHODS: Survey data from 32 patients seen in a Veterans Affairs medical center primary care clinic were collected (May 2017 to December 2017) before and after a brief appointment with a behavioral health provider. The primary outcome measure was change in pre- to post-session response to 6 items measuring perceptions of treatment taken from the Perceptions About Services Scale-Revised. RESULTS: The single behavioral health appointment resulted in improved perceptions of behavioral health treatment. Pre- to post-session ratings on 5 of 6 measured variables improved, including the perception that patients would have fewer bothersome symptoms as a result of attending a behavioral health appointment, feeling treatment would be valuable and beneficial, feeling they would have time to spend in treatment, and feeling that behavioral health specialists are understanding (Ps < .05). Patients were highly satisfied with the single integrated behavioral health session. Further, more than two-thirds of patients for whom further treatment was recommended attended a second behavioral health appointment. CONCLUSIONS: This study adds to the growing body of literature on the benefits associated with integrated behavioral health and investigates the potential mechanisms associated with the success of the single appointment.

A Naturalistic Comparison of Group Transdiagnostic Behaviour Therapy (TBT) and Disorder-Specific Cognitive Behavioural Therapy Groups for the Affective Disorders.

BACKGROUND: Transdiagnostic psychotherapies are designed to apply the same underlying treatment principles across a set of psychiatric disorders, without significant tailoring to specific diagnoses. Several transdiagnostic psychotherapy protocols have been developed recently, each of which has its own strengths and weaknesses. One promising treatment is Transdiagnostic Behaviour Therapy (TBT), in that it is one of the few transdiagnostic treatments to date shown to be effective in patients with depressive and anxiety disorders. However, TBT has only been investigated via individual psychotherapy. AIMS: The present study investigated the effectiveness of a group protocol for TBT, compared with disorder-specific group psychotherapies, in a naturalistic setting. METHOD: 109 participants with various diagnoses of affective disorders completed either group TBT (n = 37) or a disorder-specific group psychotherapy (n = 72). Measures included assessments of psychiatric symptomatology and transdiagnostic impairment at baseline and post-treatment. RESULTS: Overall, participants in the TBT group demonstrated significant improvements across all measures. When compared with disorder-specific groups, no statistical differences were observed between groups across symptoms; however, participants in the TBT group demonstrated roughly twice the treatment effect sizes in transdiagnostic impairment compared with participants in the disorder-specific groups. In addition, when participants from the most well-represented diagnosis and disorder-specific treatment (social anxiety disorder) were investigated separately, participants in the TBT group demonstrated significantly larger improvements in comorbid depressive symptoms than participants in the disorder-specific treatment. CONCLUSIONS: Pending replication and additional comparison studies, group TBT may provide an effective group treatment option for patients with affective disorders.