[Relapse prevention of bipolar disorders: an explorative cluster analytical approach in a randomized controlled psychotherapy study].

The aim of this study was to differentiate between types of bipolar disorders and the associated features using explorative analysis. The focus was particularly on the role of bipolar 1 and bipolar 2 disorders as well as the influence of prophylactic interventions for relapse in a randomized, controlled treatment study. A total of 274 of the 305 originally included persons could be investigated in the study. Patients participated in either cognitive behavioral group therapy (SEKT) or supportive, patient-centered group therapy (FEST). Treatment took place over 4 days separated by a 1-month interval (equivalent to 16 double hours). Depressive and manic symptoms were assessed using the longitudinal interval follow-up evaluation (LIFE). The symptoms were retrospectively assessed for the previous 6 months, with respect to each week before and after the intervention phase and for 6‑month and 12-month follow-ups. The results show that the effects of both group therapies were comparable; however, there were statistically significant differences in a multivariate proportional hazards model for the factors bipolar 1 and 2 as well as the interaction of therapy with bipolar 1 and 2. In particular, bipolar 2 patients benefited significantly less from the SEKT intervention than from the FEST intervention. There were three clusters identified that separated bipolar 1 (SEKT, no comorbidity, predominantly no recurrences, younger patients), from bipolar 2 (FEST, no comorbidity, at least 1 often 2 recurrences, older patients) and from a heterogeneous group (SEKT and FEST, comorbidity). The distinction between bipolar 1 and bipolar 2 disorder is important and has so far not received sufficient attention. Bipolar 2 disorders generally have a worse course and respond particularly poorly to cognitive behavioral therapy (SEKT). An open, unstructured, supportive, patient-centered psychotherapy (FEST) is generally effective.