The efficacy and tolerability of combined antidepressant treatment in different depressive subgroups

Eighty patients admitted to hospital with major depression were randomly allocated to six weeks of treatment with tranylcypromine, amitriptyline, or tranylcypromine and amitriptyline in combination, in a double-blind study. Scores on the HRSD improved significantly in all three groups, but there were no differences between the three groups. Patients on tranylcypromine and amitriptyline combined improved more according to their self-ratings after six weeks, and response was earlier as measured by a clinical global improvement scale. Those with endogenous depression improved more than those with neurotic depression, irrespective of treatment group. Combined treatment was less well tolerated than single treatments and gave rise to more side-effects, although there was no serious toxicity. Orthostatic hypotension was observed more frequently in patients on combined treatment. This group also experienced a significant increase in weight and prolongation of the P-R interval on ECG.