title: Antipsychotic-induced parkinsonism is associated with working memory deficits in schizophrenia-spectrum disorders.
abstract: In view of the significant cognitive deficits in schizophrenia and their impact on patients' social and occupational functioning, and considering that the influence potential influence of antipsychotic-induced extrapyramidal symptoms on cognition in schizophrenia remains poorly understood, the current study sought to identify the clinical, socio-demographic and neurologic predictors of the cognitive performance of schizophrenia patients. Eighty-two schizophrenia-spectrum (DSM-IV criteria) outpatients were recruited. Psychiatric symptoms were evaluated with the Positive And Negative Syndrome Scale and the Calgary Depression Scale for Schizophrenia. Extrapyramidal symptoms were evaluated with the Extrapyramidal Symptoms Rating Scale, while spatial working, planning abilities and visual paired associates learning were evaluated with the CAmbridge Neuropsychological Tests Automated Battery. The Stroop test was also administered. Multivariate hierarchic linear regression analyses were performed. We found that negative symptoms were associated with cognitive flexibility, planning, visual learning and working memory performance in schizophrenia. Age, sex, number of hospitalizations and antipsychotic type also emerged as significant predictors. More importantly, we found a significant association between antipsychotic-induced parkinsonism and working memory performance. The fact that negative symptoms and socio-demographic variables predicted cognitive performance in schizophrenia is consistent with the previous literature on the topic. The finding of an association between parkinsonism and working memory may have clinical implications, since working memory deficits are considered putative endophenotypes of schizophrenia and are known to impair patients' social and occupational functioning. Our results will need to be replicated in longitudinal studies involving larger samples of patients.
authors.affiliation: Centre de recherche de l, Institut Universitaire en Santé Mentale de Montréal, 7331 Hochelaga, Montréal, QC, H1N 3V2, Canada, stephane.potvin@umontreal.ca.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Potvin
authors.forename: Ginette
authors.initials: G
authors.lastname: Aubin
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Stip
mesh_terms: D000293:Adolescent; D000328:Adult; D014150:Antipsychotic Agents / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000150:complications*; D008570:Memory, Short-Term / Q000187:drug effects*; D008875:Middle Aged; D009483:Neuropsychological Tests; D020734:Parkinsonian Disorders / Q000139:chemically induced* / Q000150:complications*; D011237:Predictive Value of Tests; D011569:Psychiatric Status Rating Scales; D012044:Regression Analysis; D012559:Schizophrenia / Q000150:complications* / Q000188:drug therapy; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents