In these three large prospective cohorts of U.S. men and women, results indicated that suicide risk was higher among current smokers, and it increased in a nonmonotonic dose-dependent manner with increasing number of CPD. As compared with never smokers, the pooled multivariate RR of suicide was 2.7 times higher among current smokers, and was 4 times higher among those who smoked ≥25 CPD. The lack of association between duration of smoking or age at the start of smoking and suicide suggests that recent smoking behavior, especially the frequency, is associated with suicide risk.
