Lithium maintenance: factors affecting outcome.

The authors reviewed the charts of 61 manic-depressive outpatients maintained on lithium for 6--75 months for relationships between clinical outcome and various demographic, clinical, and pharmacological variables. Good outcome (50% reduction in episode frequency) did not correlate with any demographic or most natural history variables. A history of frequent episodes was correlated with decreased episode frequency but not with a lower percentage of prophylaxis failure during follow-up. A nonsignificant trend toward decreasing episode occurrence with increasing duration of lithium maintenance was present. Depression occurred considerably more frequently than manic episodes at adequate maintenance plasma lithium levels. More medication noncompliance was found among patients who experienced both manic and depressive relapses.