a1 Department of Epidemiology and Public Health, University College London, London, UK
Background Smoking cessation improves physical health but it has been suggested that in vulnerable individuals it may worsen mental health. This study aimed to identify the short- and longer-term effects of stopping smoking on depression and anxiety in the general population and in those with a history of these disorders.
Method Sociodemographic and smoking characteristics, and mental and physical health were assessed using established measures in the ATTEMPT cohort, an international longitudinal study of smokers (n = 3645). Smokers who had stopped for at least 3 months or less than 3 months at the 12-month follow-up were compared with current smokers (n = 1640).
Results At follow-up, 9.7% [95% confidence interval (CI) 8.3–11.2] of smokers had stopped for less than 3 months and 7.5% (95% CI 6.3–8.9) for at least 3 months. Compared with current smokers, prevalence of depression prescriptions obtained in the last 2 weeks was lower for those who had stopped for less than 3 months [odds ratio (OR) 0.37, 95% CI 0.14–0.96] or at least 3 months (OR 0.25, 95% CI 0.06–0.94) after adjusting for baseline prescription levels and confounding variables. Adjusted prevalence of recent depression symptoms was also lower for ex-smokers who had stopped for less than 3 months (OR 0.34, 95% CI 0.15–0.78) or at least 3 months (OR 0.24, 95% CI 0.09–0.67) than among continuing smokers. There was no change in anxiety measures in the general population or any increase in anxiety or depression symptoms in ex-smokers with a past history of these conditions.
Conclusions Smoking cessation does not appear to be associated with an increase in anxiety or depression and may lead to a reduced incidence of depression.
(Received August 15 2012)
(Revised January 29 2013)
(Accepted January 31 2013)
(Online publication March 14 2013)