To the Editor.— In his article "Abuse of Antiparkinsonism Drugs: Feigning of Extrapyramidal Symptoms To Obtain Trihexyphenidyl" (239:2365, 1978), Jonathan S. Rubinstein, MD, remarked about the scarcity of reports, such as his, involving psychotic patients using trickery to obtain prescriptions for trihexyphenidyl hydrochloride (Artane), which they may then wrongly use for hallucinogenic purposes. Certainly, as Dr Rubenstein emphasized, physicians should be more wary of the practice of automatically prescribing these antiparkinsonism agents, especially when treating patients with a long history of drug abuse. However, not all patients want the trihexyphenidyl solely to get a "high," even though they may feign an extrapyramidal reaction to obtain it. As the former director of pharmacy services at the Buffalo General Hospital Community Mental Health Center in Buffalo, my associates and I recorded an incidence of trihexyphenidyl abuse among 7% of our outpatients.1Most of our patients were welfare recipients, and two, in