Classification of depression and response to amitriptyline therapy.

Fifty-four patients suffering from primary depressive illness were rated on the Newcastle diagnostic scale while taking part in a pharmacokinetic study of amitriptyline therapy, and their clinical response was assessed by the Hamilton Rating Scale for depression. Patients with a Newcastle score of 4-8 showed the best response to amitriptyline. Patients with low Newcastle scores, representing the non-endogenous or neurotic group, responded poorly. Patients with high scores on the Newcastle scale, representing those with marked endogenous features, also responded poorly.