Lithium in tricyclic-resistant depression. Correlation of increased brain 5-HT function with clinical outcome.
Cowen PJ., McCance SL., Ware CJ., Cohen PR., Chalmers JS., Julier DL.
The addition of lithium to the tricyclic antidepressant medication of 23 patients with major depression resulted in an increase in the prolactin response to intravenous L-tryptophan after both four days and four weeks of treatment. The extent of this increase did not distinguish the ten patients who were classified as clinical responders (greater than 50% reduction in score on the HRSD). Among the responders there was a modestly significant correlation between the decrease in score on the HRSD and the enhancement of tryptophan-induced prolactin release. Some responders, however, showed very little change in this endocrine response over the four weeks of lithium treatment. Lithium may increase brain 5-HT function in tricyclic-resistant depression but there is only limited support for the hypothesis that changes in brain 5-HT function are involved in the antidepressant effect of this treatment combination.