Comparing the effectiveness of an 8-week and 12-week cognitive behavioural therapy group for bipolar affective disorder

Abstract

• Group CBT for bipolar affective disorder is effective. • No significant difference between an 8 vs 12-week CBT group for bipolar affective disorder. • Reliable and clinically significant improvement for bipolar affective disorder. Previous systematic reviews have demonstrated efficacy of Cognitive Behavioural Therapy Groups (CBT-G) in treating bipolar affective disorder (BAD). However, effectiveness research of BAD CBT-G (groups delivered in clinical practice rather than a research trial) is sparse. Additionally, the efficacy literature shows variation in the number of sessions delivered, and the number needed for clinically significant change is unclear. Therefore, we examine the effectiveness of a 12-week CBT-G compared to an 8-week group. An 8-week vs 12-week CBT-G was delivered in routine practice in an adult community mental health team. We compared pre-post data for N = 88 participants with a diagnosis of BAD who attended either an 8-week CBT-G ( n = 43) or 12-week CBT-G ( n = 45). All routine outcome measure scores which included measures related to depression, generalised anxiety, psychological distress and functioning improved significantly from baseline to treatment endpoint for both the 8-week and 12-week CBT-G interventions, with no significant differences between the groups at post-treatment. No measure for manic symptoms was included. No follow-up data was collected. The study lacks a comparator control group. This research adds to the literature in two ways by: (i) demonstrating the effectiveness of CBT-G for bipolar affective disorder; (ii) being the first to show no significant difference in outcome measures between an 8-week and 12-week group. The findings can be used to inform the provision of both a clinical and cost-effective intervention.