Is there a gap between improved symptoms and restored functioning in adults with bipolar II disorder?

Aims: This study examined differences in syndromal recovery, symptom improvement, and functional recovery over time in patients with bipolar II disorder (BD II), and how these varied by treatment and functioning domain.

Methods: Patients with BD II, currently depressed (N = 92) were randomly assigned to 20 weeks of Interpersonal and Social Rhythm Therapy (IPSRT) with placebo (IPSRT+P) or quetiapine (IPSRT+Q). Hamilton Rating Scale for Depression, Young Mania Rating Scale, and Functional Assessment Short Test were administered at weeks one, 8, 12, and 20-week follow-up. Syndromal recovery (remission), symptom improvement (50 % improvement in depressive symptoms), and functional recovery (restored functioning) were coded as binary outcomes. Longitudinal generalized linear mixed-effects models examined differences across the three outcomes over time.

Results: Functional recovery was significantly less likely to occur at all time points than symptom improvement (p < 0.01). At weeks 12 and 20, all functional recovery subdomains were less likely to occur than symptom improvement (p ≤ 0.01), except for leisure (NS). At week 8, functional recovery was more likely to occur than syndromal recovery (p = 0.01); however, this difference was not sustained at weeks 12 and 20. Differences across groups did not vary by treatment (NS) or number of previous mood episodes (NS).

Conclusions: Most patients with BD II depression showed significant improvement in depressive symptoms regardless of treatment assignment indicating that some patients can be treated with IPSRT monotherapy for depressive symptoms. Yet, the majority did not achieve functional recovery. These findings highlight the importance of prioritizing patient defined recovery in addition to considerations of symptomatic improvement in BD II treatment.