Psychological Medicine

Original Articles

Classification of depression by grade of membership: a confirmation study

Jonathan R. T. Davidsona1 c1, Max A. Woodburya1, Sidney Zisooka1 and Earl L. Giller Jr.a1

a1 Duke University Medical Center Department of Computer Science, Durham, NC, Department of Psychiatry, University of California at San Diego, Department of Psychiatry, University of Connecticut Health Center, USA


One hundred and thirty out-patients with depression were studied by grade of membership multivariate (GOM) analysis. Five depressive types were generated. Pure Type I represented a mild form of melancholia in older, stable males, who showed a modest drug response. Pure Type II included obsessive-anxious symptoms in older patients who responded well to an MAOI drug, but poorly to placebo. Pure Type III was a mildly symptomatic form of depression which responded well to placebo. Pure Type IV included features of agitation, mood worsening later in the day, anorexia and depersonalization; it was commonly precipitated by external stress and MAOI treatment was more effective than placebo. In Pure Type V depression, patients were mostly younger females with high levels of symptomatology, atypical vegetative symptoms, unstable life-styles, disadvantaged backgrounds and a poor response to MAOI and placebo. These results resemble in many ways our earlier GOM study of depression, as well as other multivariate studies of depression in the literature.


c1 Address for correspondence: Dr Jonathan R. T. Davidson, Duke University Medical Center, Psychiatry Outpatient Programs, Box 3812, Durham. North Carolina 27710, USA