MIANSERIN TREATMENT OF PATIENTS WITH PSYCHOSIS INDUCED BY ANTIPARKINSONIAN DRUGS

We evaluated the effects of mianserin, a relatively selective 5-HT2 re ceptor antagonist, on symptoms related to drug-induced psychosis in pa tients with Parkinson's disease (PD). A total of 12 patients with PD w ho had developed drug-induced psychosis showed delirium (DSM-III-R cri teria; n = 10) and pure visual hallucinations (n = 2). The antiparkins onian drugs involved in the drug-induced psychosis were L-DOPA/carbido pa, bromocriptine, trihexyphenidyl, and amantadine. They received mian serin (mean 36.7 mg, range 20-60 mg) given orally for 8 weeks. Complet e relief or marked improvement in psychotic symptoms was noted in 8 pa tients, moderate improvement in 2 patients, and no effect in 2 patient s. The parkinsonian disability also decreased slightly in 8 patients. These results suggest that serotonin antagonism at 5-HT, receptors may not only play an important role in the treatment of drug-induced psyc hosis in PD, but may also ameliorate the symptoms of parkinsonism.