Lifetime cumulative adversity, mental health and the risk of becoming a smoker.

We analyze the effect of stress exposure on the transition to heavy smoking, in a community sample of 1747 young adults in Miami, Florida. The effects of distal life stress are assessed in the context of recent stress exposure. Distal stress exposure predicts smoking independently of recent stress. Intervening stressful events do not appreciably mediate the influence of distal stress. We investigate the extent to which stress effects may be mediated by psychiatric and substance dependence disorders. We conclude that the effect of social stress on the risk for smoking is additive over time. The significant independent effect of early stress exposure implies that youths who are at greater risk for eventual heavy smoking may be identified at ages considerably younger than peak initiation age.