Studies in the relationship between depressive disorders and anxiety states. Part 1. Rating scales.

Systematic clinical examination, 7 rating scales for severity and the Newcastle Anxiety Depression Scale were applied in 117 patients with depressive, anxiety or phobic neurosis. "Endogenous" (autonomous) depressions were excluded. Principal component and discriminant function analysis were used to determine whether the depressive and anxiety syndromes could be differentiated from each other. With the aid of discriminant function analysis, separation of the 2 groups was achieved in the full sample and in 2 randomly derived sub-samples. The most powerful discriminators in all analyses were the Hamilton Depression Scale and the Newcastle Anxiety Depression Scale. Discriminant function analysis of the items from the Hamilton Depression Scale showed that it was possible to allocate 90% of the patients to the groups to which they had originally been classified by clinical diagnosis.