Smoking may be a risk factor for dementia among the elderly that erodes their problem-solving capacity and self-control and makes them see things which are not there. Severine Sabia, University College London and colleagues based their findings on the Whitehall II cohort study, involving British Civil Service employees. They examined the link between smoking and cognitive decline in the transition from midlife to old age.

They obtained data from 5,099 men and 2,137 women with average age of 56 years at the first cognitive assessment, the Archives of General Psychiatry reports.

The authors note their analysis presents four key findings. They suggest smoking in men is tied to more rapid cognitive decline and that men who continued to smoke over the follow-up experienced greater decline in all cognitive tests, according to a University College statement.

Men who quit smoking in the 10 years preceding the first cognitive measure were still at risk of greater cognitive decline, especially in executive function (an umbrella term for various complex cognitive processes involved in achieving a particular goal).

However, long-term ex-smokers did not show faster cognitive decline. "Finally, our results show that the association between smoking and cognition, particularly at older ages, is likely to be underestimated owing to higher risk of death and dropout among smokers," the authors comment.