Depressive symptomatology in drug addicts: therapeutic and aetiological implications.

213 male and female patients attending a methadone maintenance clinic completed Zung's self-rating depression scale (SDS). The mean SDS index was 53.71 (s.d. = 11.15), which falls within the morbidity range of depression as found in previous studies of psychiatric and normal populations. There was no significant correlation between methadone dosage and SDS scores. The difference between the mean SDS index of subjects on a stable dosage of methadone and subjects being detoxified was not significant. The result may have important theoretical and practical implications with respect to the role of depression in addiction.