Adolescent mental health predicts quitting smoking in adulthood: a longitudinal analysis

Objectives: Several studies have reported an association between cigarette smoking and psychiatric illness. A common finding is that the prevalence of psychiatric illness among former smokers is much lower than among current smokers and is often similar to that among never-smokers. There are two alternative causal explanations for this association: either improved mental well-being results from smoking cessation; or those with poorer mental well-being are less successful at smoking cessation. The objective was to analyse a unique longitudinal data set to shed light on the direction of causality and to distinguish between these alternative explanations. Methods: Information on smoking status and indicators of poor mental well-being from childhood and adolescence was collected at age 18 in 1969 from 49321 men at compulsory conscription for military service. Follow-up data on smoking status were collected among a random subset (n 694) who participated in one or more annual national Swedish Surveys of Living Conditions in 1981–2001. Results: Approximately half of the smokers at age 18 in 1969 had quit by the time they were resurveyed (1981–2002). Those who had not quit and who reported smoking more than 10 cigarettes/day at age 18 (called persistent heavy smokers), were more likely to have had childhood and adolescent indicators of poor mental health measured at age 18 in 1969 than non-smokers or quitters. Conclusion: Our findings indicate that men who would subsequently be successful at smoking cessation reported better mental health and a lower prevalence of childhood mental health indicators at age 18 than persistent heavy smokers