Objective To examine the use of selective serotonin reuptake inhibitors (SSRIs) among Danish women of childbearing age according to lifestyle factors.

Design Cross-sectional survey.

Setting The Central Denmark Region.

Participants 4234 women (71.5% of the invited women) aged 25–44 years who participated in a public health survey in 2006.

Outcome measures Prevalence and prevalence ratios (PRs) of current and former SSRI use among women characterised by selected lifestyle factors. We obtained information on SSRI use through linkage to the Aarhus University Prescription Database covering all pharmacies in the region.

Results Of the 4234 women in the study, 161 (3.8%) were current SSRI users, 60 (1.4%) were recent users, 223 (5.3%) were former users and 3790 (89.5%) were never users. Current use of SSRIs was more prevalent in obese women than in non-obese women (PR 1.5, 95% CI 1.0 to 2.3), in current smokers compared with non-current smokers (PR 1.6, 95% CI 1.1 to 2.2), in women who drank more than seven alcoholic drinks weekly compared with women who drank seven or fewer drinks weekly (PR 1.8, 95% CI 1.2 to 2.8) and in women with an unhealthy diet compared with women with a healthy diet (PR 1.7, 95% CI 1.2 to 2.6). Prevalence of former use of SSRIs was similarly increased except in those with an unhealthy diet (PR 1.1, 95% CI 0.8 to 1.7). SSRI use did not differ according to participation in regular physical activity.

Conclusions Women with an unhealthy lifestyle were about 1.5-fold more likely to be current or former users of SSRIs than those with a healthy lifestyle. These findings may be useful for quantitative assessment of the contribution of lifestyle factors to uncontrolled confounding in studies of SSRI use in pregnancy.