Weight gain in relation to major depression and antidepressant medication use

Previous studies have linked major depressive episodes (MDEs) to obesity. The association may be partially mediated by antidepressant medication use. In the current study we examine changes in weight and BMI in relation to MDE and antidepressant use in a general population cohort.

Data from a Canadian longitudinal study, the National Population Health Survey (NPHS) were used. The NPHS has collected data from a community cohort since 1994 using interviews spaced two years apart. The NPHS includes the Composite International Diagnostic Interview Short Form for Major Depression (CIDI-SFMD). Self-reported height and weight are also recorded. Linear regression was used to describe associations between weight, BMI and MDE.

The pattern of weight change varied by age. Respondents under the age of 65 tended to gain weight over time, whereas those over the age of 65 tended to lose weight. Respondents in the younger category gained more weight if they had MDE or took antidepressant medications. However, the extent of weight gain was modest, those with MDE and those taking an antidepressant gaining an average of approximately 1 kg over 12 years of follow-up.

The study used self-reported weight, which may be inaccurate. Measurements were made two years apart. The measure of MDE was an abbreviated diagnostic interview.

Both MDE and antidepressant medication use are associated with a modest increase in weight in people under 65. These results may be useful for physicians and other health professionals in planning dietary and weight-management regimens for depressed patients.