Five-year outcome of bipolar I and II disorders: findings of the Jorvi Bipolar Study

Abstract

Objectives: The long-term outcome of bipolar disorder (BD) has been extensively investigated. However, previous studies may be biased towards hospitalized patients with bipolar I disorder (BD-I), and generalizability to the current treatment era remains uncertain. In this naturalistic study, we followed a secondary-care cohort of patients with BD.

Methods: In the Jorvi Bipolar Study, 191 patients with BD-I and bipolar II disorder (BD-II) were followed using a life-chart method. Interviews were conducted at six months, 18 months, and five years. Time to full remission, time to first recurrence, total time ill, their predictors, and BD-I versus BD-II differences were investigated among the 151 patients remaining in follow-up.

Results: Nearly all subjects recovered from the index episode, but almost all (90%) had a recurrence, and most had multiple recurrences. The patients spent about one-third of their time in illness episodes and 15% of their time with subthreshold symptoms; half of the time they were euthymic. After controlling for confounders, no difference in time spent in depressive states between patients with BD-I and BD-II persisted. Among patients with a depressive index phase, cluster C personality disorders [hazard ratio (HR) = 0.452, p = 0.040] and higher 17-item Hamilton Depression Scale score (HR = 0.951, p = 0.022) predicted longer time to remission, whereas lifetime psychotic symptoms (HR = 2.162, p = 0.016) predicted shorter time to first recurrence.

Conclusions: Among patients with BD, chronicity as uninterrupted persistence of illness was rare, but multiple recurrences were the norm. Patients with BD spent only half of their time euthymic. Patients with BD-I and BD-II may differ little in proneness to depressive states. Severity of depression, cluster C personality disorders, and psychotic symptoms predicted outcome.

Keywords: bipolar disorder; cohort studies; outcome; recurrence; remission.