“…The LPD depression score has been shown to correlate highly with the Zung depression score, r = 0.88 (Byrne, 1975). Although there must inevitably be false positives and negatives in the allocation of patients on the basis of the decision rule to the endogenous depression, nonendogenous depression and non-depressive syndromes, such a categorisation is significantly associated not only with clinical diagnosis (Pilowsky, 1969;Byrne, 1975;Pilowsky, 1979), but with treatment choice (Pilowsky and McGrath, 1970) and certain psychophysiological measures (Byrne, 1975).…”