Lithium carbonate response in depression. Prediction by unipolar/bipolar illness, average-evoked response, catechol-O-methyl transferase, and family history.

The antidepressant efficacy of lithium carbonate was assessed in a double-blind trial in 23 hospitalized depressed patients. Unequivocal response was significantly more frequent in bipolar than in unipolar depressed patients. Lithium carbonate responders had a greater visual average-evoked response amplitude increase in response to increased stimulus intensity, termed "augmenting". No correlation could be demonstrated between lithium carbonate efficacy and either erythrocyte catechol-O-methyl transferase activity, age of symptom onset, number of hospitalizations, or family history of affective disorders.