The prevalence of depression symptoms after smoking cessation: a systematic review and meta-analysis

Objectives: Smoking cessation can have positive effects on people's health, especially mental health. This study aimed to address the prevalence of depression in the smoking cessation population. Methods: In the present meta-analysis study, PRISMA protocol was used. Two databases, PubMed and Scopus, were selected. Articles in these two databases in English were targeted and the search was limited to July 2020. First, the results related to the prevalence of depression were calculated. The results were pooled. Results: Forty-nine articles with different designs were eligible for meta-analysis. The prevalence of depression in the smoking cessation population was 18% and the confidence interval was 14-22%. The highest depression prevalence was in Asia and Europe, followed by America. The prevalence of major depression in the smoking cessation population was 15% and the prevalence of depressive symptoms was 17%. The smoking cessation population had a lower odds of depression than current smokers (OR= 0.63 CI = 0.54-0.75; I2 83.9%). There was little evidence for publication bias. Discussion: The status of depression in the smoking cessation population is different from that of nonsmokers and current smokers. Therefore, in terms of health policy and encouraging people to smoking cessation, the issue of its positive effects on mental health should be emphasized.