The effect size is similar to that of antidepressant treatment.
Many smokers cite relief of psychological symptoms as a reason for
continued smoking. However, the relation between smoking and mental
health is unclear. In this meta-analysis of 26 prospective,
observational studies conducted in various countries worldwide,
investigators compared changes in mental health (anxiety, depression,
mixed anxiety and depression, quality of life, positive affect, and
stress) at ≥6 weeks’ post–smoking cessation with changes after the
same amount of time among people who continued to smoke.
After a median follow-up of 6 to 12 months, smoking cessation,
compared with continued smoking, was associated with significant
decreases in anxiety, depression, mixed anxiety and depression, and
stress and significant increases in psychological quality of life and
positive affect (all measured via questionnaires). The effect size was
similar between participants from general populations and those with
physical or psychiatric illnesses.
COMMENT
In this study, smoking cessation was associated with improved mental
health outcomes. Although these observational associations do not
prove causality, they do challenge widely held beliefs that smoking
relieves psychological symptoms and that trying to quit smoking
aggravates such symptoms. As the authors note, if the associations are
causal, the effect size of smoking cessation is similar to that of
drug treatment for depression or generalized anxiety disorder. At
least, these results should inspire us to be more proactive in
encouraging smoking cessation among patients with anxiety and
depression.
Taylor G et al. Change in mental health after smoking cessation:
Systematic review and meta-analysis. BMJ 2014 Feb 13; 348:g1151. (http://dx.doi.org/10.1136/bmj.g1151
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