A positive psychology intervention for patients with bipolar depression: a randomized pilot trial.

Background: There are few effective treatments for bipolar depression, a common and debilitating illness. Aims: We aimed to examine the feasibility and preliminary efficacy of a four-week, telephone-delivered positive psychology (PP) intervention for patients with bipolar depression. Methods: Twenty-five patients hospitalized for bipolar depression were randomized to receive a PP (n = 14) or control condition (CC; n = 11) intervention. Following discharge, participants completed weekly exercises and phone calls with a study trainer. PP intervention feasibility was assessed by the number of exercises completed, and acceptability was examined on five-point Likert-type scales of ease and utility. Between-group differences on psychological constructs at 4 and 8 weeks post-enrollment were assessed using mixed effects regression models. Results: Participants in the PP group completed an average of three out of four PP exercises and found PP exercises to be subjectively helpful, though neither easy nor difficult. Compared to CC, the PP intervention led to trends towards greater improvements in positive affect and optimism at follow-up, with large effect sizes (modified Cohen's d = 0.95-1.24). PP had variable, non-significant effects on negative psychological constructs. Conclusions: Larger, randomized trials are needed to further evaluate the efficacy of this intervention in this high-risk population.