An Evaluation of the Effects of Diagnostic Composition on Individual Treatment Outcome Within Transdiagnostic Cognitive–Behavioral Group Therapy for Anxiety

Recently, studies have supported the efficacy of treating anxiety disorders utilizing a transdiagnostic, or non-diagnosis-specific, framework (Erickson, D. H. (2003). Group cognitive behavioural therapy for heterogeneous anxiety disorders. Cognitive Behaviour Therapy, 32, 179–186; Garcia, M. S. (2004). Effectiveness of cognitive-behavioural group therapy in patients with anxiety disorders. Psychology in Spain, 8, 89–97; Norton, P. J., & Hope, D. A. (2005). Preliminary evaluation of a broad-spectrum cognitive-behavioral group therapy for anxiety. Journal of Behavior Therapy and Experimental Psychiatry, 36, 79–97). Transdiagnostic group treatment packages focus on the common aspects inherent across the anxiety disorders such as behavioral and cognitive avoidance, and faulty cognitive appraisals of threat potential or meaning (Barlow, D. H., Allen, L. B., & Choate, M. L. (2004). Toward a unified treatment for emotional disorders. Behavior Therapy, 35, 205–230). Although research supports the overall efficacy of transdiagnostic cognitive behavior therapy (CBT) for anxiety disorders (Norton, P. J., & Philipp, L. M. (2008). Transdiagnostic approaches to the treatment of anxiety disorders: A quantitative review. Psychotherapy: Theory, Research, Practice and Training, 45, 214–226), the effect of diagnostically mixed group composition on individual outcomes is less clear. This study investigated the relationship between group composition and treatment outcome within diagnostically heterogeneous groups with the purpose of determining if diagnostic heterogeneity differentially impacted treatment outcome for 84 individuals during a 12-week transdiagnostic cognitive–behavioral group anxiety treatment program (Norton, P. J. (2012a). Group cognitive-behavioral therapy of anxiety: A transdiagnostic treatment manual. New York: Guilford). The diagnostic makeup of the treatment group was examined at the beginning of treatment and at the end of treatment, and the results indicated that the diagnostic makeup of the treatment group had no significant impact on individual treatment outcome. These findings have direct implications for the delivery of transdiagnostic treatments, and are discussed in terms of their global implications for the transdiagnostic approach to the treatment of anxiety disorders.     

Transdiagnostic Internet treatment for anxiety disorders: A randomized controlled trial

Clinician-guided Internet-based cognitive behavioural therapy (iCBT) programs are clinically effective at treating specific anxiety disorders. The present study examined the efficacy of a transdiagnostic Internet-based cognitive behavioural treatment (iCBT) program to treat more than one anxiety disorder within the same program (the Anxiety Program). Eighty six individuals meeting diagnostic criteria for generalized anxiety disorder (GAD), panic disorder, and/or social phobia were randomly assigned to a treatment group, or to a waitlist control group. Treatment consisted of CBT based online educational lessons and homework assignments, weekly email or telephone contact from a clinical psychologist, access to a moderated online discussion forum, and automated emails. An intention-to-treat model using the baseline-observation-carried-forward principle was employed for data analyses. Seventy-five percent of treatment group participants completed all 6 lessons within the 8 week program. Post-treatment data was collected from 38/40 treatment group and 38/38 control group participants, and 3-month follow-up data was collected from 32/40 treatment group participants. Relative to controls, treatment group participants reported significantly reduced symptoms of anxiety as measured by the Generalized Anxiety Disorder - 7 Item, Social Phobia Screening Questionnaire, and the Panic Disorder Severity Rating Scale - Self Report Scale, but not on the Penn State Worry Questionnaire, with corresponding between-groups effect sizes (Cohen’s d) at post-treatment of 0.78, 0.43, 0.43, and 0.20, respectively. The clinician spent a total mean time of 46 min per person over the program, participants rated the procedure as moderately acceptable, and gains were sustained at follow-up. Modifications to the Anxiety program, based on post-treatment feedback from treatment group participants, were associated with improved outcomes in the control group. These results indicate that transdiagnostic programs for anxiety disorders may be successfully administered via the Internet.     

E-mailed standardized cognitive behavioural treatment of work-related stress: a randomized controlled trial

The aim of this study was to assess the effects of a 7-week standardized cognitive behavioural treatment of work-related stress conducted via e-mail. A total of 342 people applied for treatment in reaction to a newspaper article. Initial screening reduced the sample to a heterogeneous (sub)clinical group of 239 participants. Participants were assigned randomly to a waiting list condition (n = 62), or to immediate treatment (n = 177). A follow-up was conducted 3 years after inception of the treatment. The outcome measures used were the Depression Anxiety Stress Scales (DASS-42) and the Emotional Exhaustion scale of the Maslach Burnout Inventory - General Survey (MBI-GS). Fifty participants (21%) dropped out. Both groups showed statistically significant improvements. Intention-to-treat analysis of covariance (ANCOVAs) revealed that participants in the treatment condition improved significantly more than those in the waiting control condition (0.001

or = d > or = 0.5 (anxiety)). The between-group effects ranged from d = 0.6 (stress) to d = 0.1 (anxiety). At follow-up, the effects were more pronounced, but this result requires replication in view of high attrition at follow-up. The results warrant further research on Internet-driven standardized cognitive behavioural therapy for work-related stress. Such research should include the direct comparison of this treatment with face-to-face treatment, and should address the optimal level of therapist contact in Internet-driven treatment.     

Transdiagnostic internet treatment for anxiety and depression: a randomised controlled trial

Disorder-specific cognitive behavioural therapy programs delivered over the internet (iCBT) with clinician guidance are effective at treating specific anxiety disorders and depression. The present study examined the efficacy of a transdiagnostic iCBT protocol to treat three anxiety disorders and/or depression within the same program (the Wellbeing Program). Seventy-seven individuals with a principal diagnosis of major depression, generalised anxiety disorder, panic disorder, and/or social phobia were randomly assigned to a Treatment or Waitlist Control group. Treatment consisted of CBT-based online educational lessons and homework assignments, weekly email or telephone contact from a clinical psychologist, access to a moderated online discussion forum, and automated emails. Eighty one percent of Treatment group participants completed all 8 lessons within the 10 week program. Post-treatment data were collected from 34/37 Treatment group and 35/37 Control group participants, and 3-month follow-up data were collected from 32/37 Treatment group participants. Relative to Controls, Treatment group participants reported significantly reduced symptoms of anxiety and depression as measured by the Depression Anxiety and Stress Scales-21 item, Patient Health Questionnaire-9 item, and Generalised Anxiety Disorder-7 item scales, with corresponding between-groups effect sizes (Cohen’s d) at post treatment of.56,.58, and.52, respectively. The clinician spent a mean time of 84.76 min (SD = 50.37) per person over the program. Participants rated the procedure as highly acceptable, and gains were sustained at follow-up. These results provide preliminary support for the efficacy of transdiagnostic iCBT in the treatment of anxiety and depressive disorders.     

Unified protocol for transdiagnostic treatment of emotional disorders: a randomized controlled trial

This study further evaluates the efficacy of the Unified Protocol for Transdiagnostic Treatment of Emotional Disorders (UP). A diagnostically heterogeneous clinical sample of 37 patients with a principal anxiety disorder diagnosis was enrolled in a randomized controlled trial (RCT) involving up to 18 sessions of treatment and a 6-month follow-up period. Patients were randomly assigned to receive either immediate treatment with the UP (n=26) or delayed treatment, following a 16-week wait-list control period (WLC; n=11). The UP resulted in significant improvement on measures of clinical severity, general symptoms of depression and anxiety, levels of negative and positive affect, and a measure of symptom interference in daily functioning across diagnoses. In comparison, participants in the WLC condition exhibited little to no change following the 16-week wait-list period. The effects of UP treatment were maintained over the 6-month follow-up period. Results from this RCT provide additional evidence for the efficacy of the UP in the treatment of anxiety and comorbid depressive disorders, and provide additional support for a transdiagnostic approach to the treatment of emotional disorders.     

The influence of comorbidity on treatment outcome for children and adolescents with anxiety disorders

There have been a growing number of studies showing that cognitive behavioural treatment packages for children with anxiety disorders are highly effective. Clinically, it is often assumed that treatment outcome is less successful, or that treatment needs to be altered when faced with the existence of comorbid conditions. To date, only one study has directly addressed this question in the child anxiety literature. The present study compared the treatment outcome and maintenance following a brief, group program for the reduction of child and adolescent anxiety disorders in anxious children with versus without comorbid disorders. There was no significant difference in response to treatment at the end of the program and few differences at 12-month follow-up. The only indication of an impact of comorbidity was a suggestion that children with a comorbid condition did not do as well at follow-up. However, this result was only shown on some parent-report measures and not on self-report measures. Overall, the results indicate that treatment for child and adolescent anxiety disorders produces broadly comparable results regardless of the existence of comorbid disorders.     

Reducing depression in 9–10 year old children in low SES schools: A longitudinal universal randomized controlled trial

The Aussie Optimism: Positive Thinking Skills Program (AOP-PTS) is an innovative curriculum-based mental health promotion program based on cognitive and behavioural strategies. The program is aimed at preventing depressive and anxiety symptoms and disorders in middle primary school children aged 9–10 years. Students from 22 low SES primary schools (N = 910) were randomly assigned to an intervention or a control group and assessed at baseline, post-test, 6 months and 18 months. The intervention group received the program implemented by teachers and the control group received their regular Health Education curriculum. Students completed questionnaires on depression, anxiety, and attribution style. At risk students were further assessed with the computerised Diagnostic Interview for Children and Adolescents. Parents reported on their children's externalising and internalising problems at home. Children in the intervention condition reported a significant pre-post reduction in depressive symptoms, and there was a significant pre-post reduction in parent-reported emotional difficulties which was maintained at 6 month follow-up; no changes were evident in the control group. Both groups showed significant improvements in child-reported anxiety and attribution style, and significant improvements in parent-reported pro-social behaviours. For both groups, there were no significant post-baseline changes in incidence and recovery rates for depression, anxiety, or internalising symptoms. These findings suggest that AOP-PTS has the potential to treat depressive symptomatology in the immediate term but the effects were not sustained. There is also evidence of improved emotional resilience up to 6 months following the program. Further follow-up to investigate longer term effects is needed.     

Long-Term Effects of an Internet-Based Treatment for Posttraumatic Stress

Abstract

Advances in communication technology offer additional strategies for providing psychological treatment. Previous trials of Internet-based treatment approaches reported significant reductions in posttraumatic stress and related symptoms in response to Internet-based treatments relative to control groups. However, empirical data on the long-term effects of those approaches are sparse. In order to evaluate the long-term effect of an Internet-based intervention, the authors conducted an 18-month follow-up of an Internet-based cognitive behavioural therapy for posttraumatic stress. Severity of posttraumatic stress symptoms was the primary outcome. Additional measures were depression, anxiety, mental and physical health, and health care utilization during the follow-up period. Treatment group participants (n = 34) were assessed 1.5 years after completing treatment. Results indicated that reductions in symptoms of posttraumatic stress symptoms, depression, and anxiety found at posttreatment were sustained during the 18-month follow-up period. Preliminary evidence on long-term effects of Internet-based health care as shown in this study is promising. However, research with larger and clinically more diverse samples is needed to fully assess the clinical impact and potential of Internet-based health care provision.     

The role of perfectionism in cognitive behaviour therapy outcomes for clinically anxious children

The main aim of this study was to determine whether pre-treatment levels of child perfectionism impacted on anxiety treatment outcomes for school-aged children. In addition, it was investigated whether child perfectionism decreased following treatment for anxiety. Participants were sixty-seven clinically anxious children aged 6–13 years (female = 34; majority Caucasian) who were enrolled in a group-based cognitive behaviour therapy program, and their parents. They completed self-report questionnaires on anxiety and depressive symptoms and were administered a diagnostic interview to determine the type and clinician rated severity of anxiety and related disorders pre- and post-treatment and at 6-month follow-up. Self- and parent-rated perfectionism were also measured pre-treatment, while a subset of children completed perfectionism measures post-treatment as well. Self-Oriented Perfectionism, but not Socially Prescribed Perfectionism, predicted poorer self-reported treatment outcome (higher levels of anxiety symptoms) immediately following treatment and at 6-month follow-up when using a multi-informant approach. Additionally, both Self-Oriented and Socially Prescribed child perfectionism significantly reduced immediately following treatment. Despite reductions in child perfectionism following anxiety treatment, higher Self-Oriented Perfectionism may impact negatively on child anxiety treatment outcome.     

Relationship between homework completion and outcome in cognitive behaviour therapy

Homework or between-session learning has long been considered an essential aspect of effective cognitive behaviour therapy. However, it has received relatively less empirical attention than other components of cognitive behaviour therapy. In general, studies have found that homework completion is predictive of outcome in psychotherapy. However, the amount of homework completed by a patient represents only one aspect of this important therapeutic component. This study investigated both the quantity and the quality of homework completed during a 10-week group cognitive and behavioural treatment program for anxious and depressed patients. It explored the relationship between various aspects of homework completion and outcomes on several different variables. A total of 94 patients were included in the analysis. It was found that both quantity and quality of homework completed predicted outcome on measures of depression, anxiety and quality of life at post-treatment and at 1-month follow-up. The results were strongest for the amount of homework completed, suggesting that clinicians should encourage patients to complete homework even if the homework content is not entirely accurate. The results of this study highlight the importance of homework as a central part of effective cognitive and behavioural treatment.     

Usability and Utility of a Computerized Cognitive-Behavioral Self-Help Program for Public Speaking Anxiety

This study describes the use of a cognitive-behavioral computer-administered self-help program with minimal therapist contact for public speaking anxiety. Participants (N = 10) with social phobia, as measured by a structured clinical interview, completed the self-help program in an open clinical trial. The program was delivered via a CD-ROM during individual sessions at an outpatient clinic, including 4 sessions of psychoeducation/cognitive therapy and 4 sessions of exposure therapy using a virtual audience presented on a computer screen. A therapist was available in another room to answer questions and to debrief for up to 10 minutes after each session. Participants completed standardized self-report questionnaires assessing social anxiety at pretreatment, posttreatment, and 3-month follow-up. Participants also completed measures of computer usability. Results showed decreases on all self-report measures of social anxiety from pre- to posttreatment, which were maintained at follow-up (n = 8). Participants also reported that they were satisfied with treatment, that they felt improved after treatment, and that the computer program was user-friendly. This study provides preliminary evidence that a computer-administered cognitive-behavioral-based program that includes minimal therapist contact may reduce public speaking anxiety and suggests that further research with a controlled design is needed.     

Prevention of anxiety symptoms in children: results from a universal school-based trial

The present study evaluated the effectiveness of a universal school-based cognitive behavior prevention program (the FRIENDS program) for childhood anxiety. Participants were 638 children, ages 9 to 12 years, from 14 schools in North Rhine-Westphalia, Germany. All the children completed standardized measures of anxiety and depression, social and adaptive functioning, coping strategies, social skills, and perfectionism before and after the 10-week FRIENDS program and at two follow-up assessments (6 and 12 months) or wait period. Children who participated in the FRIENDS program exhibited significantly fewer anxiety and depressive symptoms, and lower perfectionism scores than children in the control group at 12-month follow-up. Younger children (9-10-year-olds) displayed treatment gains immediately after the intervention, whereas older children (11-12-year-olds) showed anxiety reduction only at 6- and 12-month follow-up. Perfectionism and avoidant coping acted as mediators of pre- to postintervention changes in anxiety scores. This study provides empirical evidence for the utility of the FRIENDS program in reducing anxiety and depressive symptoms among German children.     

Randomized controlled trial of false safety behavior elimination therapy: a unified cognitive behavioral treatment for anxiety psychopathology

We tested the efficacy of a unified cognitive-behavioral therapy protocol for anxiety disorders. This group treatment protocol, termed false safety behavior elimination therapy (F-SET), is a cognitive-behavioral approach designed for use across various anxiety disorders such as panic disorder (PD), social anxiety disorder (SAD), and generalized anxiety disorder (GAD). F-SET simplifies, as well as broadens, key therapeutic elements of empirically validated treatments for anxiety disorders to allow for easier delivery to heterogeneous groups of patients with anxiety psychopathology. Patients with a primary anxiety disorder diagnosis (N=96) were randomly assigned to F-SET or a wait-list control. Data indicate that F-SET shows good efficacy and durability when delivered to mixed groups of patients with anxieties (i.e., PD, SAD, GAD) by relatively inexperienced clinicians. Findings are discussed in the context of balancing treatment efficacy and clinical utility.     

Effectiveness of an Individualized Case Formulation-Based CBT for Non-responding Youths with Anxiety Disorders

The study examined the effectiveness of an individualized case formulation-based cognitive behavior therapy (CBT) for youths (9–17 years) with anxiety disorders and their parents after unsuccessful treatment with a manualized group CBT program (the Cool Kids). Out of 106 participant youths assessed at a 3-month follow-up after manualized CBT, 24 were classified as non-responders on the Clinical Global Impression-Improvement scale (CGI-I), and 14 of 16 non-responders with anxiety as their primary complaint accepted an offer for additional individual family CBT. The treatment was short-term (M sessions = 11.14) and based on a revised case formulation that was presented to and agreed upon by the families. At post-treatment, nine youths (64.3 %) were classified as responders on the CGI-I and six (42.9 %) were free of all anxiety diagnoses, while at the 3-month follow-up 11 (78.6 %) had responded to treatment and nine (64.3 %) had remitted from all anxiety diagnoses. Large effect sizes from pre- to post-individualized treatment were found on youths’ anxiety symptoms, self-reported (d = 1.05) as well as mother-reported (d = .81). There was further progress at the 3-month follow-up, while treatment gains remained stable from post-treatment to the 1-year follow-up. Results indicate that non-responders to manualized group CBT for youth anxiety disorders can be helped by additional CBT targeting each family’s specific needs.     

CBT intensity and outcome for panic disorder in a primary care setting

A hybrid efficacy-effectiveness design in which participants (n = 91/93) were retained in the study regardless of whether or not they received treatment enabled evaluation of CBT intensity in relation to panic disorder in the primary care setting. CBT intensity was operationalized as number of cognitive-behavioral therapy sessions, number of follow-up booster phone calls, and secondarily, as number of cognitive behavioral coping and exposure strategies. Baseline psychosocial and demographic predictors of CBT intensity were analyzed first. Severity of anxiety sensitivity predicted number of cognitive behavioral sessions, but no baseline variables predicted number of follow-up booster phone calls or number of coping and exposure strategies. Multivariate logistic and linear regressions were used to evaluate the degree to which treatment intensity predicted 3-month and 12-month outcomes (anxiety sensitivity, phobic avoidance, depressive symptoms, disability, and medical and mental health functioning) after controlling for potential confounding baseline variables. Number of cognitive behavioral therapy sessions predicted lower anxiety sensitivity at 3 and 12 months, and number of follow-up booster phone calls predicted lower anxiety sensitivity, less phobic avoidance, and less depression at 12 months. These findings indicate that "dose" of psychotherapy was an important predictor of outcome. The significance of follow-up booster phone contact is discussed as an index of continued self-management of panic and anxiety following acute treatment.     

Cognitive therapy for post-traumatic stress disorder: development and evaluation

The paper describes the development of a cognitive therapy (CT) program for post-traumatic stress disorder (PTSD) that is based on a recent cognitive model (Behav. Res. Therapy 38 (2000) 319). In a consecutive case series, 20 PTSD patients treated with CT showed highly significant improvement in symptoms of PTSD, depression and anxiety. A subsequent randomized controlled trial compared CT (N = 14) and a 3-month waitlist condition (WL, N = 14). CT led to large reductions in PTSD symptoms, disability, depression and anxiety, whereas the waitlist group did not improve. In both studies, treatment gains were well maintained at 6-month follow-up. CT was highly acceptable, with an overall dropout rate of only 3%. The intent-to-treat effect sizes for the degree of change in PTSD symptoms from pre to post-treatment were 2.70-2.82 (self-report), and 2.07 (assessor-rated). The controlled effect sizes for CT versus WL post-treatment scores were 2.25 (self-report) and 2.18 (assessor-rated). As predicted by the cognitive model, good treatment outcome was related to greater changes in dysfunctional post-traumatic cognitions. Patient characteristics such as comorbidity, type of trauma, history of previous trauma, or time since the traumatic event did not predict treatment response, however, low educational attainment and low socioeconomic status were related to better outcome.     

Evaluation of a Combined Cognitive Behavioural Therapy and Interpersonal Process Group in the Psychotherapy Training of Clinical Psychologists

It is now widely acknowledged that both content and process elements of psychotherapy play a part in client treatment outcomes. Despite this, there are pressures on Australian clinical psychology training programs to teach evidence‐based approaches in a relatively short time frame. Producing clinical psychology graduates who have an adequate level of competence in evidence‐based practice and meeting the demands of professional accreditation requirements can mean that less time is available to teach the process elements of psychotherapy. The aim of this study was to conduct a preliminary evaluation of a clinical psychology psychotherapy training program that combines an interpersonal process group with a cognitive behavioural therapy training model that incorporates self‐reflection and self‐practice. Eleven participants who participated in the training in 2008 completed the Counseling Self‐Estimate Inventory at pre‐ and post‐training. Significant improvements on the majority of the subscales of this inventory were found. A separate sample of nine trainees and clinical psychology registrars who also previously completed the program attended individual interviews in 2010 aimed at gaining their perspective regarding various aspects of the program. Self‐practice of cognitive behavioural therapy techniques was found to be important in the identification and management of trainees’ own core beliefs, and to their appreciation of how challenging this process may be for clients. The interpersonal process group was described by participants as enhancing their competency as psychotherapists. Common themes included the experience of anxiety and a high level of emotion, and understanding how this experience might be similar for clients; increased self‐awareness; and increased competence in process issues. Many participants believed the process and content components of training were equally important to their development as psychotherapists.     

School-based prevention of anxiety using the “My FRIENDS” emotional resilience program: Six-month follow-up

Anxiety-related problems are common in childhood and adolescence and, if left untreated, may hold short-term and long-term negative consequences for psychosocial functioning and other domains. In addition to having negative individual-level consequences, anxiety-related problems may have a negative impact at the school level. Because almost all children and adolescents attend school, school plays a significant role in development as a socialisation agent and provides an ideal venue for the delivery of prevention and intervention programs. Here, we present the first evidence regarding the effectiveness of the My FRIENDS emotional resilience program as a method of reducing anxiety among students in Slovenia and the feasibility of implementing the program at the national level. Grade 8 students (N = 78) were assigned either the intervention condition, the My FRIENDS program, or a no-treatment control condition. We measured general anxiety and its components using the AN-UD (Lestvica anksioznosti za učence in dijake) anxiety scale and internalising difficulties using the Strengths and Difficulties Questionnaire at preintervention, postintervention, and 6-month follow-up assessments. Students in the intervention condition reported lower amounts of general anxiety and its cognitive component of worrying, and fewer internalising difficulties at the postintervention and follow-up assessments.     

A Randomized Trial of Cognitive Behaviour Therapy and Cognitive Therapy for Children with Posttraumatic Stress Disorder Following Single-Incident Trauma

The present study compared the efficacy of trauma-focused cognitive behavior therapy (CBT) with trauma-focused cognitive therapy (without exposure; CT) for children and youth with posttraumatic stress disorder (PTSD). Children and youth who had experienced single-incident trauma (N = 33; 7–17 years old) were randomly assigned to receive 9 weeks of either CBT or CT which was administered individually to children and their parents. Intent-to-treat analyses demonstrated that both interventions significantly reduced severity of PTSD, depression, and general anxiety. At posttreatment 65% of CBT and 56% of the CT group no longer met criteria for PTSD. Treatment completers showed a better response (CBT: 91%; CT: 90%), and gains were maintained at 6-month follow-up. Maternal depressive symptoms and unhelpful trauma beliefs moderated children’s outcome. It is concluded that PTSD secondary to single-incident trauma can be successfully treated with trauma-focused cognitive behavioural methods and the use of exposure is not a prerequisite for good outcome.     

Influence of co-morbid generalized anxiety disorder, panic disorder and personality disorders on the outcome of cognitive behavioural treatment of obsessive-compulsive disorder

This study examined co-morbid generalized anxiety disorder and/or panic disorder and personality disorders as predictors of treatment outcomes in adult outpatients with obsessive-compulsive disorder. The patients received exposure with response prevention (ERP) treatment with the addition of either elements of cognitive therapy (ERP+CT) or relaxation training (ERP+REL). It was hypothesized that the addition of cognitive interventions would yield better treatment outcomes for patients with co-morbid generalized anxiety disorder and/or panic disorder. It was also hypothesized that patients with any personality disorder would show less treatment gains in both conditions. Using intention-to-treat criteria, patients with generalized anxiety disorder and/or panic disorder co-morbidity showed less treatment gains at post-treatment across both treatment conditions. This group showed significantly more treatment gains in the ERP+CT condition at the post-treatment and the 12-month follow-up assessments compared with patients in the ERP+REL condition. However, this was not significant when comparing treatment completers. Patients with a co-morbid Cluster A or B personality disorder showed significantly less treatment gains in both treatment conditions at the 12-month follow-up assessment. Among treatment completers, patients with a Cluster C personality disorder showed significantly better outcomes at the post-treatment assessment in the ERP+REL treatment condition. These results, clinical implications, and the importance of further investigations are discussed.