Smoking and Parkinson's disease.

A total of 443 patients with Parkinson's disease and a similar number of age and sex matched controls were interviewed as regards their smoking habits. A lower proportion of the patients (26.4%) had smoked when compared with the controls (32.7%). Similarly, the patients had more often stopped smoking (76.1%) than the controls (53.8%). The difference in the proportions of persons who smoked in these two groups may be explained by selective mortality, or alternatively, by premorbid behavior of Parkinson's disease patients.