Context: Numerous studies have pointed to the failure of prophylaxis with pharmacotherapy alone in the treatment of bipolar I disorder. Recent investigations have demonstrated benefits from the addition of psychoeducation or psychotherapy to pharmacotherapy in this population.

Objective: To compare 2 psychosocial interventions: interpersonal and social rhythm therapy (IPSRT) and an intensive clinical management (ICM) approach in the treatment of bipolar I disorder.

Design: Randomized controlled trial involving 4 treatment strategies: acute and maintenance IPSRT (IPSRT/IPSRT), acute and maintenance ICM (ICM/ICM), acute IPSRT followed by maintenance ICM (IPSRT/ICM), or acute ICM followed by maintenance IPSRT (ICM/IPSRT). The preventive maintenance phase lasted 2 years.

Setting: Research clinic in a university medical center.

Participants: One hundred seventy-five acutely ill individuals with bipolar I disorder recruited from inpatient and outpatient settings, clinical referral, public presentations about bipolar disorder, and other public information activities.

Interventions: Interpersonal and social rhythm therapy, an adaptation of Klerman and Weissman's interpersonal psychotherapy to which a social rhythm regulation component has been added, and ICM.

Main outcome measures: Time to stabilization in the acute phase and time to recurrence in the maintenance phase.

Results: We observed no difference between the treatment strategies in time to stabilization. After controlling for covariates of survival time, we found that participants assigned to IPSRT in the acute treatment phase survived longer without a new affective episode (P = .01), irrespective of maintenance treatment assignment. Participants in the IPSRT group had higher regularity of social rhythms at the end of acute treatment (P<.001). Ability to increase regularity of social rhythms during acute treatment was associated with reduced likelihood of recurrence during the maintenance phase (P = .05).

Conclusion: Interpersonal and social rhythm therapy appears to add to the clinical armamentarium for the management of bipolar I disorder, particularly with respect to prophylaxis of new episodes.