The effects of ‘‘acute’’ cigarette smoking on cognitive functioning in chronic schizophrenia

Abstract

Introduction. The prevalence of cigarette smoking among patients with schizophrenia is high. Nicotine stimulates acetylcholine (ACh) transmission, and patients with schizophrenia may suffer from reduced ACh activity due to the combined effects of antipsychotic and antiparkinsonian drug treatment. The present study was designed to test whether cigarette smoking is, in part, an adaptive response among patients with schizophrenia to temporarily enhance cognitive functioning through an increase in ACh tone. Methods. Thirty-three inpatients with chronic schizophrenia treated with either clozapine (high in anticholinergicity) or risperidone (low anticholinergicity) were administered a cognitive test battery under two experimental conditions: Acute Smoking and Abstinence. Results. Results showed a modest and fairly specific enhancement effect for smoking. During Acute Smoking a subset of patients on clozapine required less time to complete a test of attentional vigilance. Also, a significant interaction appeared such that subjects treated with clozapine demonstrated better discriminability under the Acute Smoking condition. Conclusions. The data are consistent with other findings suggesting a specific link between attentional functioning and nicotinic acetylcholine activity, and lend support to the ‘‘cognitive enhancement’’ hypothesis for cigarette smoking in terms of producing subtle benefits for selected functions in cognitively impaired schizophrenia patients who are experiencing medication-related anticholinergic burden.