Investigated extrapyramidal features and socioclinical factors predisposing psychiatric patients to misuse trihexyphenidyl (Artane). 30 patients with 2 major functional psychoses and abusing trihexyphenidyl were compared with 90 Artane non-abusers. Besides a detailed clinical interview, each patient was assessed by using Diagnostic and Statistical Manual of Mental Disorders-III-Revised (DSM-III-R) criteria, Brief Psychiatric Rating Scale, Simpson and Angus Scale, and Abnormal Involuntary Movement Scale. Results show that trihexyphenidyl abusers were significantly characterized by being ever-married, unemployed, smoking and having past and concurrent history of multiple drug abuse, and genetic loading of mental disorders. Besides other socioclinical parameters, premorbid personalities, stressful life events and extrapyramidal symptoms including tardive dyskinesia did not differentiate the 2 groups. Artane abusers, when compared with non-abusers, were significantly less characterized by negative psychopathology. However, other psychopathological domains including depressive and positive symptoms did not differentiate between abusers and non-abusers. It is recommended that psychiatrists should not prescribe trihexyphenidyl indiscriminately and for a long time to these patients, who indeed require long-term antipsychotic maintenance medications.