Effects of alcohol and cigarette use on cognition in middle-aged adults

In this retrospective cohort study we examined the independent and interactive effects of drinking and smoking on cognition in a sample of 3361 males, ages 31 to 49, with varying lifetime histories of alcohol and cigarette use. Dependent variables were neuropsychological measures of global and specific cognitive abilities. Comparison of the ability scores of seven groups, defined by their drinking and smoking histories, explained only 5.4% of the multivariate variance in cognitive ability and less than 2% in any individual cognitive measure. Regression analyses for current drinkers and smokers showed only a single significant, but negligible, effect of pack-years of smoking on a measure of global cognitive ability. Differences in cognitive function in groups defined by intensity of alcohol and cigarette use revealed no significant effect for drinking and a significant, but very small, effect for smoking.