Background: Prospective data on the association between common mental disorders and obesity are scarce, and the impact of ageing on this association is poorly understood.
Aims: To examine the association between common mental disorders and obesity (body mass index > or = 30 kg/m(2)) across the adult life course.
Method: The participants, 6820 men and 3346 women, aged 35-55 were screened four times during a 19-year follow-up (the Whitehall II study). Each screening included measurements of mental disorders (the General Health Questionnaire), weight and height.
Results: The excess risk of obesity in the presence of mental disorders increased with age (P = 0.004). The estimated proportion of people who were obese was 5.7% at age 40 both in the presence and absence of mental disorders, but the corresponding figures were 34.6% and 27.1% at age 70. The excess risk did not vary by gender or according to ethnic group or socioeconomic position.
Conclusions: The association between common mental disorders and obesity becomes stronger at older ages.