The link between neuropsychological impairments and chronic tobacco smoking is not clear and in the current literature there is a lack of robust analyses investigating this association. A systematic review of the literature was conducted in order to identify relevant longitudinal and cross-sectional studies conducted from 1946 to 2017. A meta-analysis was performed from 24 studies testing the performance of chronic tobacco smokers compared with non-smokers on neuropsychological tests related to eight different neuropsychological domains. The results revealed a cross-sectional association between neuropsychological impairments and chronic tobacco smoking in cognitive impulsivity, non-planning impulsivity, attention, intelligence, short term memory, long term memory, and cognitive flexibility, with the largest effect size being related to cognitive impulsivity (SDM=0.881, p <0.005), and the smallest effect size being related to intelligence (SDM=0.164, p<0.05) according to Cohen's benchmark criteria. No association was found between chronic smoking and motor impulsivity (SDM=0.105, p=0.248). Future research is needed to investigate further this association by focusing on better methodologies and alternative methods for nicotine administration.

Methodological issues such as small sample sizes, heterogeneity and poor quality limited the interpretation of the results and does not address whether the observed impairments reflect co-morbid functioning, methadone-related sedation and/or other factors. Only higher quality longitudinal studies will permit confident interpretation of the results observed in this meta-analysis.

No abstract

No abstract