Objective To investigate change in mental health after smoking cessation compared with continuing to smoke. Design Systematic review and meta-analysis of observational studies. Data sources Web of Science, Cochrane Central Register of Controlled Trials, Medline, Embase, and PsycINFO for relevant studies from inception to April 2012. Reference lists of included studies were hand searched, and authors were contacted when insufficient data were reported. Eligibility criteria for selecting studie...
