Evaluation of the combination of tryptophan and ECT in the treatment of depression. I. Clinical analysis.

A double-blind evaluation of the antidepressant efficacy of treatment with a combination of orally administered L-tryptophan (L-TP) and electroconvulsive therapy (ECT) was made in patients suffering from endogenous depression. The patients were randomly assigned to two groups, one treated with L-TP (6 g daily) and unilateral ECT, the other with placebo and unilateral ECT. L-TP treatment was initiated at least 1 day before the first ECT and terminated 4 days after the last ECT. There was a good agreement between the two groups in several measures of antidepressant efficacy: doctors' and patients' ratings of depressive symptoms, and doctors' global rating of therapeutic effect 4 days and 1 month after the last ECT. In the L-TP group, however, there was a significantly better effect on retardation symptoms in the nurses' rating scale. This difference, which is not consistent with other measures of amelioration, contributes, at most, to a marginal therapeutic addition to the antidepressant effect of ECT. It is concluded that oral administration of L-TP, in the dose of 6 g daily, is not of practical value for potentiating the antidepressant efficacy of ECT.