Objective:
To examine the association between antidepressant use and weight gain, as well as the interaction with lifestyle factors.
Design:
Longitudinal study
Setting and participants:
We used data from 2334 adults from two stages (4.4 years apart) of the North West Adelaide Health Study, including validated diet and lifestyle questionnaires, measured body weight, and linked pharmaceutical data.
Main outcome measures:
Body weight change
Results:
188 (8.1%) participants had a mean annual number of 1-2 antidepressant prescriptions, and 212 (9.1%) had over 2 prescriptions. The mean annual weight gain was 0.12, 0.18 and 0.28 kg in non-users, low (1-2 prescriptions/year) and high (>2 prescriptions/year) antidepressant users, respectively. In multivariable regression models, antidepressant use was positively associated with weight gain: high antidepressant users gained an extra 0.22 (95%CI 0.00-0.44) kg per year. This association was mainly due to selective serotonin reuptake inhibitor (SSRI) use. High SSRI users gained 0.48 (95%CI 0.20-0.76) kg more than non-users. There was no association between tricyclics or other antidepressant use and weight gain. The association between SSRI use and weight gain was mainly seen among those with high intake of Western diet, sedentary activity, and smoking.
Conclusions:
Exposure to SSRIs potentiates weight gain, exceeding what occurs in the context of Western diet, sedentarism, and smoking without antidepressant exposure.