Differences of Cognitive Function and Treatment Response between Smoking and Non-smoking Schizophrenic Patients

Namkoong, Kee; Min, Sung Kil; Lee, Hee Sang; Cho, Hyun Sang; Kim, Se Joo

Abstract

OBJECTIVES
The purpose of this study was to examine the differences of past histories, current symptoms, treatment responses and cognitive functions between smoking and nonsmoking schizophrenic patients.
METHODS
The subjects were composed of 67 schizophrenic patients including 36 smokers and 31 non-smokers. They were examined by psychiatric history checklist, Simpson and Angus's rating scale for extrapyramidal side effects, positive and negative syndromes scale(PANSS), global assessment scale(GAS), and Vienna test including Standard Progressive Matrices(SFM), Cognitron, and Flicker Fusion Analyzer(FFA).
RESULTS
The results were as follows: 1) Although the duration of illness of smokers was longer than that of non-smokers, the smokers had significantly higher score of GAS and significantly lower score of PANSS than non-smokers at admission 2) With effects of age and duration of illness controlled, there were no differences of mean dosage of neuroleptics, extrapyramldal side effects, PANSS improvement rate and GAS improvement rate between both groups. 3) With effects of age, duration of illness, and total PANSS score controlled, there were no differences of score of SFM, cognitron, and FFA. 4) In smokers, the PANSS improvement rate and the GAS improvement rate were positively correlated with mean number of daily smoked cigarettes, with effects of age and duration of illness controlled.
CONCLUSIONS
In schizophrenic patients, smokers had less severe symptoms than non-smokers. In smokers, the PANSS improvement rate and the GAS improvement rate were positively correlated with mean number of daily smoked cigarettes. But smokers were not proven to have received higher dosage of neuroleptics, to have lower extrapyramidal side effects, or to have less severe impairment of cognitive function.