Group acceptance and commitment therapy (ACT) for bipolar disorder and co-existing anxiety - an open pilot study

Previous studies have supported acceptance and commitment therapy (ACT) for reducing impairment related to various chronic conditions. ACT may possibly be beneficial for bipolar disorder (BD) with co-existing anxiety, which is associated with a poorer treatment outcome. Efforts are needed to identify suitable psychological interventions for BD and co-existing anxiety. In this open clinical trial, we included 26 patients with BD type 1 or 2 at an outpatient psychiatric unit specializing in affective disorders. The intervention consisted of a 12-session manualized group treatment that included psychoeducation, mindfulness, engaging in values-based behaviour, cognitive defusion, acceptance and relapse prevention modules. Participants completed four self-report questionnaires covering anxiety symptoms (Beck Anxiety Inventory - BAI), depressive symptoms (Beck Depression Inventory - BDI-II), quality of life (Quality of Life Inventory - QOLI) and psychological flexibility (Acceptance and Action Questionnaire - AAQ-2) before, during and after the treatment. At post-treatment, the participants reported significant improvements in all outcome measures, with large effects (Cohen's d between 0.73 and 1.98). The mean reduction in anxiety symptoms was 45%. At post-treatment, 96% of the patients were classified as responders on at least one of the outcome measures. A limitation is that the trial is uncontrolled. The results suggest that ACT has the potential to be an effective treatment for BD patients with co-existing anxiety. Further randomized studies are warranted.