The British Journal of Psychiatry
A Double-Blind Trial of Phenelzine and Amitriptyline in Depressed Out-Patients. A Possible Differential Effect of the Drugs on Symptoms


In a double-blind trial, 62 depressed out-patients were given either phenelzine or amitriptyline. The groups were compared in respect of: (1) the drop-out rate during one month; (2) the anti-depressant effect at one month, measured by the change in scores on the Hamilton, Beck and Lubin scales in patients remaining on the drugs; (3) the differential association of individual features with response to treatment as measured by these scales. The Eysenck Personality Inventory (EPI) was also given to measure `neuroticism' and `extraversion' before and after treatment.

The drop-out rate was significantly higher (P < .05) in patients receiving amitriptyline than in those receiving phenelzine, mainly due to side effects. At one month, there was a trend on all three scales for patients still taking amitriptyline to have improved more than those still taking phenelzine, and the difference on the Beck scale was significant (P < .02), though it ceased to be so when a difference in the initial scores was taken into account. The change in EPI N scores, however, was significantly greater (P < .01) in patients receiving amitriptyline even after allowing for the difference in initial scores, suggesting that the effect of this drug, in depressed out-patients, is due to an improvement in neurotic features as well as in depressive symptoms. Evidence was found that, in the doses used, the response to the two drugs was related to a differential effect on individual features.