Endogenous depression as a construct: a quantitative analysis of the literature and a study of clinician judgements.

We review the concept of endogenous depression historically and undertake quantitative analyses of representative factor analytic studies. We also report an empirical study, isolating symptoms and signs associated with a clinical diagnosis of psychotic/endogenous depression, made by a large number of clinical raters assessing 300 depressives. The quantitative analyses and the study of practising psychiatrists agreed in delineating depressive type and together suggest a more restricted construct of endogenous and psychotic depression than has been held historically. Key clinical features isolated were severity, retardation, delusions and paranoid features, non-reactivity and non-variability in mood, while vegetative features appeared to lack relevance.