Predictors of immediate response in the treatment of mania: the importance of comorbidity.

Four hundred thirty-eight bipolar manics were admitted to an acute care psychiatric inpatient ward over a 12-year period. Eighty percent had good and 20% poor immediate outcome. Good outcome patients were characterized by short episode duration, older age of onset, a longer hospitalization, fewer suicide thoughts, and less psychiatric and medical comorbidity than the poor outcome group. Patients were divided into four treatment groups based on primary mode of therapy during index hospitalization: electroconvulsive therapy (ECT), adequate lithium, inadequate lithium, and neither treatment. Patients experiencing good outcome were more likely to be in the adequate lithium group and less likely to receive neither treatment. Regression analysis identified the absence of comorbidity, duration of lithium treatment more than 2 weeks, and duration of episode of less than 1 month as predictors of good outcome at hospital discharge.