Clozapine, negative symptoms, and extrapyramidal side effects
Kane, J.M.; Safferman, A.Z.; Pollack, S.; Johns, C.; Szymanski, S.; Kronig, M.; Lieberman, J.A.
Journal of Clinical Psychiatry 55(Suppl): 74-77
1994
ISSN/ISBN: 0160-6689 PMID: 7961579 Document Number: 424897
The importance of persistent negative symptoms in schizophrenia as a limiting factor in psychosocial and vocational rehabilitation has been increasingly emphasized. As a result, treatment trials and new drug development programs are focusing more attention on negative symptoms. Unfortunately, there is enormous phenomenological overlap between negative symptoms and neuroleptic-induced parkinsonism. We report data from a cohort of 56 clozapine-treated patients demonstrating significant correlations between measures of akinesia and anergia. Despite an average drug washout of over 2 weeks, the persistence of drug-induced parkinsonism can confound the assessment of therapeutic drug effects on negative symptoms.