Forty-one patients who had failed to respond to 8 weeks of treatment
with 20 mg of fluoxetine were randomly assigned to one of three treatments
for 4 weeks: 40-60 mg/day of fluoxetine, 20 mg/day of fluoxetine plus 25-50
mg/day of desipramine, and 20 mg/day of fluoxetine plus 300-600 mg/day of
lithium. Patients treated with high- dose fluoxetine (N = 15) did
significantly better than patients treated with fluoxetine plus lithium (N
= 14) and those treated with fluoxetine plus desipramine (N = 12).
High-dose fluoxetine was the most effective treatment among partial
responders to previous treatment, but high-dose fluoxetine and fluoxetine
plus lithium were the most effective treatments among nonresponders.