The Newcastle Endogenous Depression Diagnostic Index: validity and reliability.

The newcastle Endogenous Depression Diagnostic Index of Carney et al. was studied for reliability and validity. Good inter-rater reliability was obtained for diagnostic category and for item scores in 36 patients. The scale showed construct validity with reference to the Hamilton and Montgomery-Asberg rating scales. Concurrent validity was shown relative to other diagnostic scales of endogenous depression. Predictive validity was demonstrated in that endogenous and nonendogenous depressive responded differently to isocarboxazid. The continued use of 5 as the point of separation between endogenous and nonendogenous depression is questionable.