Smoking and mental health - NCSCT

Smoking and mental health
mental illnesses (because the characteristics between these two groups are
probably more similar than between those with schizophrenia and the general
population); the combined estimates were 2.3 (95% CI 2.0–2.7, 14 studies) and
1.8 (95% CI 1.5–2.3, 8 studies) for males and females, respectively.
4.7 Smoking and anxiety disorders
Table A4 summarises the main design features and findings from 18 prospective
studies identified from the literature search. Due to the different methods of
assessments and definitions of exposures and outcome measures, a formal metaanalysis
was not performed.
Eleven studies investigated whether people with anxiety disorders were more
likely either to be smokers or to take up smoking. 21,23,24,38–45 Of these, five
reported clear positive associations, 23,38–41 five found non-significant positive
correlations 21,24,42–44 and one 45 found a decreased risk. Of studies of the uptake
of smoking in relation to anxiety at baseline, 21,24,39–41 two found strong increases
in risk (OR = 3.85, 95% CI 1.34–11.0 39 and OR = 1.9, 95% CI 1.3–2.8 41 ) whereas
three found modest or non-significant associations. 21,24,40
Eight studies examined whether smokers at baseline were more likely to
develop anxiety disorders later. 3,26,43,46–50 Five of these were based on teenagers
and three on adults (18–64 years). ORs for onset of anxiety were increased in six
of the studies that reported effect sizes: 5.53 (95% CI 1.84–16.66), 50 1.88 (95%
CI 1.15–3.06), 3 1.46 (95% CI 1.15–1.86), 49 3.23 (95% CI 1.0–10.8) 46 and 2.32
(95% CI 1.19–4.53). 47 Increased risks were also seen in the two studies of effect
of smoking on post-traumatic stress disorder: 5.1 (95% CI 1.2–21.5) 48 and 2.64
(95% CI 1.05–6.62). 47 One study reported a positive regression coefficient
between baseline smoking status and subsequent anxiety score. 43 Only one study
reported a reduced risk associated with daily smoking; however, this effect was
not statistically significant (RR = 0.9, p = 0.8). 26
4.8 Smoking and eating disorders
Three prospective cohort studies of the association between eating disorders and
the onset of smoking were identified 51–53 (see Table A5), all involving 1 year of
follow-up in adolescents aged 11–15 years at baseline. In one of the studies,
binge eating or purging was not significantly related to smoking uptake in males
(OR = 0.7, 95% CI 0.1–4.1) or females (binge eating: OR = 1.8, 95% CI 0.9–3.5;
purging: OR = 2.0, 95% CI 0.8–4.9). 51 However, in the other two studies, the
risk of onset of smoking was found to be significantly associated with body
dissatisfaction and/or eating pathology (OR = 4.33, 95% CI 1.71–10.95), 52 and
in those with a high eating disorder symptom score in girls (OR = 2.15, 95% CI
1.16–3.97) but not in boys (OR = 1.67, 95% CI 0.91–3.07). 53 One of the
70 © Royal College of Physicians 2013