Effectiveness of Individual Cognitive-Behavioral Therapy and Predictors of Outcome in Adult Patients with Obsessive-Compulsive Disorder.

INTRODUCTION: Cognitive-behavioral therapy (CBT) for obsessive-compulsive disorder (OCD) has proven its efficacy in randomized controlled trials (RCTs). OBJECTIVE: To test generalizability to routine care settings, we conducted an effectiveness study to provide naturalistic outcome data and their predictors. METHODS: Pre-post changes in symptoms and impairment as well as response rates were determined in a naturalistic OCD sample (intention-to-treat, ITT, n = 393). Patients received individual CBT for OCD adopting an exposure-based, non-manualized treatment format. Linear and logistic regression analyses were applied to identify associations of sociodemographic and clinical variables with symptom change. RESULTS: Effect size in ITT patients amounted to d = 1.47 in primary outcome (Yale-Brown Obsessive-Compulsive Scale, Y-BOCS). Remission rates were 46.3% (ITT), 52.0% (completers), and 18.2% (non-completers). The rates of treatment response without remission, no change, and deterioration in the ITT sample were 13.2, 38, and 3%, respectively. Initial symptom severity, comorbid personality disorder, and unemployment were associated with a poorer outcome, and previous medication with a better outcome. Comorbid depressive and anxiety disorders as well as other clinical or sociodemographic variables showed no effects on symptom change. CONCLUSIONS: Outcomes in this large observational trial in a naturalistic setting correspond to available RCT findings suggesting that CBT for OCD should be strongly recommended for dissemination in routine care. Targets for further research include early prediction of non-response and development of alternative treatment strategies for patients who respond insufficiently.

Mechanisms of exposure and response prevention in obsessive-compulsive disorder: effects of habituation and expectancy violation on short-term outcome in cognitive behavioral therapy.

BACKGROUND: Exposure and response prevention is effective and recommended as the first choice for treating obsessive-compulsive disorders (OCD). Its mechanisms of action are rarely studied, but two major theories make distinct assumptions: while the emotional processing theory assumes that treatment effects are associated with habituation within and between exposure sessions, the inhibitory learning approach highlights the acquisition of additional associations, implying alternative mechanisms like expectancy violation. The present study aimed to investigate whether process variables derived from both theories predict short-term outcome. METHOD: In a university outpatient unit, 110 patients (63 female) with OCD received manual-based cognitive-behavioral therapy with high standardization of the first two exposure sessions. Specifically, therapists repeated the first exposure session identically and assessed subjective units of distress as well as expectancy ratings in the course of exposure sessions. Based on these data, individual scores for habituation and distress-related expectancy violation were calculated and used for prediction of both percentage change on the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) and remission status after 20 therapy sessions. RESULTS: In a multiple regression model for percentage change, within-session habituation during the first exposure was a significant predictor, while in a logistic regression predicting remission status, distress-related expectancy violation during the first exposure revealed significance. A path model further supported these findings. CONCLUSIONS: The results represent first evidence for distress-related expectancy violation and confirm preliminary findings for habituation, suggesting that both processes contribute to treatment benefits of exposure in OCD, and both mechanisms appear to be independent.

Identifying CBT non-response among OCD outpatients: A machine-learning approach.

Objectives: Machine learning models predicting treatment outcomes for individual patients may yield high clinical utility. However, few studies tested the utility of easy to acquire and low-cost sociodemographic and clinical data. In previous work, we reported significant predictions still insufficient for immediate clinical use in a sample with broad diagnostic spectrum. We here examined whether predictions will improve in a diagnostically more homogeneous yet large and naturalistic obsessive-compulsive disorder (OCD) sample. Methods: We used sociodemographic and clinical data routinely acquired during CBT treatment of n = 533 OCD subjects in a specialized outpatient clinic. Results: Remission was predicted with 65% (p = 0.001) balanced accuracy on unseen data for the best model. Higher OCD symptom severity predicted non-remission, while higher age of onset of first OCD symptoms and higher socioeconomic status predicted remission. For dimensional change, prediction achieved r = 0.31 (p = 0.001) between predicted and actual values. Conclusions: The comparison with our previous work suggests that predictions within a diagnostically homogeneous sample, here OCD, are not per se superior to a more diverse sample including several diagnostic groups. Using refined psychological predictors associated with disorder etiology and maintenance or adding further data modalities as neuroimaging or ecological momentary assessments are promising in order to further increase prediction accuracy.

Long-Term Stability of Benefits of Cognitive Behavioral Therapy for Obsessive Compulsive Disorder Depends on Symptom Remission During Treatment.

Background: Cognitive behavioral therapy (CBT) is an effective treatment for obsessive-compulsive disorder (OCD) and may afford stable long-term improvements. It is not clear, however, how stability or symptom recurrence can be predicted at the time of termination of CBT. Method: In a 1-year follow-up intention-to-treat study with 120 OCD patients receiving individual CBT at a university outpatient unit, we investigated the predictive value of international consensus criteria for response only (Y-BOCS score reduction by at least 35%) and remission status (Y-BOCS score ≤ 12). Secondly, we applied receiver-operating characteristic (ROC) curves in order to find an optimal cut-off score to classify for deterioration and for sustained gains. Results: Response only at post-treatment increased the likelihood of deterioration at follow-up compared to remission at an odds ratio of 8.8. Moreover, ROC curves indicated that a post-treatment score of ≥ 13 differentiated optimally between patients with and without symptom deterioration at follow-up assessment. The optimal cut-off score to classify for any sustained gains (response, remission, or both) at follow-up relative to baseline was 12. Importantly, previous findings of generally high long-term symptom stability after treatment in OCD could be replicated. Conclusion: The findings highlight the clinical importance of reaching remission during CBT, and suggest that a recently published expert consensus for defining remission has high utility.