A `double-blind' trial designed to test the efficacy of amitriptyline over a seven month period was undertaken in 132 depressed patients treated with ECT. A control group selected at random was given diazepam. Both drugs were given from the commencement of ECT.

Progress was assessed (i) by recording `failures', i.e. drop outs from the trial, and the reasons for them; and (ii) by administering rating scales, on entry, and at one, four and seven months (a 5-grade clinical scale, the Hamilton scale, and two self-rating scales, the Beck and the Lubin).

In patients remaining on the drug at one month there was a significant advantage to the amitriptyline group on two of the four rating scales used. During the remainder of the trial fewer patients in this group committed suicide, had further ECT, or failed to improve. Side-effects, however, were more troublesome.

A possible depressant effect of diazepam is considered. The importance of maintenance therapy and of adequate supervision in the after-care of ECT treated depressive patients is indicated by the occurrence of three suicides in the group not receiving the anti-depressant drug.