1. Comparison between unadjusted and adjusted SMDs and 95% CIs for the association between smoking cessation compared to continued smoking and mental health from studies in which both were presented.

Study	Outcome	Covariates adjusted for	Unadjusted SMD (95% CI)	Adjusted SMD (95% CI)
Becoña 2017	Depression	Treatment group allocation, age, sex, baseline marital status, baseline education level, baseline working status, baseline FTND score, baseline number of years smoking	−1.61 (−2.34 to −0.88)	−1.62 (−2.36 to −0.88)
Blalock 2008	Depression	Baseline carbon monoxide expiration, baseline nicotine withdrawal score, treatment group allocation	−0.54 (−1.42 to 0.34)	−0.58 (−1.01 to −0.15)
McDermott 2013	Anxiety	Baseline STAI score, age, baseline nicotine dependence level, baseline cigarette consumption, and treatment group allocation	−0.62 (−0.88 to −0.36)	−0.74 (−1.00 to −0.48)
Taylor 2015	Psychological quality of life	Baseline FTND score, treatment group allocation, age started smoking, baseline report of calming effects from smoking, baseline report of unpleasant symptoms from smoking, baseline length of time to last cessation attempt, baseline experience from last cigarette, baseline longest period without smoking, baseline SF‐36 mental health score	1.37 (0.41 to 2.33)	1.13 (0.13 to 2.13)