Cigarette Smoking and Cognitive Decline in Midlife: Evidence From a Prospective Birth Cohort Study

OBJECTIVES: The authors investigated the effects of cigarette smoking on midlife cognitive performance. METHODS: Multiple regression was used to test the association between cigarette smoking and changes in cognitive test scores among male and female members of the British 1946 birth cohort aged between 43 and 53 years. RESULTS: Smoking was associated with faster declines in verbal memory and with slower visual search speeds. These effects were largely accounted for by individuals who smoked more than 20 cigarettes per day and were independent of sex, socioeconomic status, previous (adolescent) cognitive ability, and a range of health indicators. CONCLUSIONS: The present results show that heavy smoking is associated with cognitive impairment and decline in midlife. Smokers who survive into later life may be at risk of clinically significant cognitive declines.