A link between smoking and suicide was observed as early as 1976 by Doll and Peto10 in their study of mortality due to smoking in male British doctors. Clinical and epidemiological studies that subsequently investigated the issue are in general, but not universal, agreement in finding a significant association between smoking and suicide and suicidal behaviours. Among studies that focused on SRO, three that used cross-sectional epidemiological data found a positive correlational association between smoking and SRO.11–13 Of seven longitudinal studies that also used community-based data, three14–16 found that current smoking predicted suicidal behaviours even after controlling for the effects of demographic and psychiatric variables; four studies did not find a positive relationship.17–20
