Chemically, trimipramine has an imino-benzyl nucleus and a side-chain resembling that of methotrimeprazine [5-(3-dimethyl-amino-2-methyl-propyl)-10, 11-dihydrodibenz (b, f,) azepine]. In “double blind” controlled comparisons of trimipramine and imipramine, Salzmann (1965) in 27 hospitalized depressed patients who did not require ECT, found the two drugs not significantly different in effect. Blumenthal and Seppala (1965) obtained similar results. Burns (1965), however, in 44 patients suffering from psychotic depression, found trimipramine to be significantly superior at the 5 per cent. level to imipramine in ratings of recovery from depression, anxiety and insomnia. No difference was found in the latency interval between the drugs.