Patients suffering from mixed anxiety/depressive states referred to a psychiatric out-patient clinic completed a four course of either a once-daily table of 30 mg nortriptyline with 1-5 mag fluphenazine, or a sustained release capsule of 50 mg amitriptyline once daily, on a double-blind basis. Depression improved satisfactorily on either treatment, but there was a greater reduction of anxiety on fluphenazine/nortriptyline, Drowsiness, however, occurred more frequently among the patients on amitriptyline, suggesting the sedative properties of this drug did not substitute adequately for a specific anxiolytic effect. Dry mouth was also noticeably more frequent with amitriptyline. As might be expected on pharmacokinetic and phsyological grounds, the results suggest that the sustained release characteristics of the amitriptyline preparation lead to a maximization of side-effects during the day without conferring any therapeutic advantage.