Cognitive behaviour therapy and supportive therapy for bipolar disorders: relapse rates for treatment period and 2-year follow-up

Background. The efficacy of adjunctive psychosocial interventions such as cognitive behaviour therapy (CBT) for bipolar disorder (BD) has been demonstrated in several uncontrolled and controlled studies. However, these studies compared CBT to either a waiting list control group, brief psycho-education or treatment as usual (TAU). Our primary aim was to determine whether CBT is superior to supportive therapy (ST) of equal intensity and frequency in preventing relapse and improving outcome at post-treatment. A secondary aim was to look at predictors of survival time. Method. We conducted a randomized controlled trial (RCT) at the Department of Psychology, University of Tubingen, Germany (n=76 patients with BD). Both CBT and ST consisted of 20 sessions over 9 months. Patients were followed up for a further 24 months. Results. Although changes over time were observed in some variables, they were not differentially associated with CBT or ST. CBT showed a non-significant trend for preventing any affective, specifically depressive episode during the time of therapy. Kaplan-Meier survival analyses revealed that 64.5% of patients experienced a relapse during the 33 months. The number of prior episodes, the number of therapy sessions and the type of BD predicted survival time. Conclusions. No differences in relapse rates between treatment conditions were observed, suggesting that certain shared characteristics (e.g. information, systematic mood monitoring) might explain the effects of psychosocial treatment for BD. Our results also suggest that a higher number of prior episodes, a lower number of therapy sessions and a diagnosis of bipolar II disorder are associated with a shorter time before relapse.