Quitting smoking does not increase the risk of major depressive episodes among users of Internet smoking cessation interventions

Psychol Med. 2010 Mar;40(3):441-9. doi: 10.1017/S0033291709990560. Epub 2009 Jul 23.


Background: Limited evidence has suggested that quitting smoking increases the incidence of major depressive episodes (MDEs), particularly for smokers with a history of depression. Further evidence for this increase would have important implications for guiding smoking cessation.

Method: Spanish- and English-speaking smokers without a current MDE (n=3056) from an international, online smoking cessation trial were assessed for abstinence 1 month after their initial quit date and followed for a total of 12 months. Incidence of screened MDE was examined as a function of abstinence and depression history.

Results: Continued smoking, not abstinence, predicted MDE screened at 1 month [smoking 11.5% v. abstinence 7.8%, odds ratio (OR) 1.36, 95% confidence interval (CI) 1.04-1.78, p=0.02] but not afterwards (smoking 11.1% v. abstinence 9.8%, OR 1.05, 95% CI 0.77-1.45, p=0.74). Depression history predicted MDE screened at 1 month (history 17.1% v. no history 8.6%, OR 1.71, 95% CI 1.29-2.27, p<0.001) and afterwards (history 21.7% v. no history 8.3%, OR 3.87, 95% CI 2.25-6.65, p<0.001), although the interaction between history and abstinence did not.

Conclusions: Quitting smoking was not associated with increased MDE, even for smokers with a history of depression, although a history of depression was. Instead, not quitting was associated with increased MDE shortly following a quit attempt. Results from this online, large, international sample of smokers converge with similar findings from smaller, clinic-based samples, suggesting that in general, quitting smoking does not increase the incidence of MDEs.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cohort Studies
  • Depressive Disorder, Major / diagnosis
  • Depressive Disorder, Major / epidemiology*
  • Depressive Disorder, Major / psychology*
  • Female
  • Follow-Up Studies
  • Humans
  • Incidence
  • Internationality
  • Internet*
  • Male
  • Odds Ratio
  • Predictive Value of Tests
  • Psychiatric Status Rating Scales / statistics & numerical data
  • Risk Factors
  • Self-Help Groups
  • Smoking Cessation / methods*
  • Smoking Cessation / psychology*
  • Smoking Cessation / statistics & numerical data