Defining the clinical course of bipolar disorder: response, remission, relapse, recurrence, and roughening.

OBJECTIVE: This manuscript presents working definitions for key clinical course indicators for bipolar disorder, including response, remission, relapse, recurrence, and roughening.
METHOD: A work group of experts in bipolar disorder reviewed prior efforts to define clinical course indicators for unipolar depression and for schizophrenia. Using these efforts as templates, the work group developed consensus operational definitions. The rationale for each of the definitions was a point of time when a treatment decision needed to be made.
RESULTS: The group defined response as a 50% reduction in a score from a standard rating scale of symptomatology from an appropriate baseline, regardless of index episode type (manic, depressed, or mixed). In addition, the other pole cannot be significantly worsened during response. Remission was defined as absence or minimal symptoms of both mania and depression for at least 1 week. Sustained remission requires at least eight consecutive weeks of remission, and perhaps as many as 12 weeks. A relapse/recurrence was defined as a return to the full syndrome criteria of an episode of mania, mixed episode, or depression following a remission of any duration. Roughening was defined as a return of symptoms at a subsyndromal level, perhaps representing a prodrome of an impending episode.
CONCLUSIONS: The work group recommends that all reports of clinical trials in bipolar disorder include results using these definitions. This will introduce standards for such reports. Hopefully, the definitions will be revised and improved over time.