The endogenous--neurotic distinction as a predictor of response to antidepressant drugs.

An inverse factor analysis of 880 depressed inpatients on 33 endogenous-neurotic variables yielded four patient types. Type 3 resembled the endogenous depressions and Type 2 the neurotic depressions. Type 3 patients responded well to both imipramine and chlorpromazine and did poorly on a placebo. Type 2 patients showed the greatest overall improvement at three weeks irrespective of treatment received, including a placebo.