Prevalence of comorbid depression and obesity in general practice: a cross-sectional survey

Background: General practice is a common setting for the provision of weight-management advice, as well as the treatment of depression. While there is some evidence of a reciprocal relationship between obesity and depression, there are limited data about the rates of depression among general practice patients who are underweight, normal weight, overweight, and obese. Aim: To explore the prevalence of depression among underweight, normal weight, overweight, and obese general practice patients. Design and setting: A cross-sectional survey was conducted in 12 Australian general practices. Method: Patients aged ≥18 years and older who were presenting for general practice care were eligible to participate. Consenting patients completed a touchscreen computer survey assessing self-reported weight and height. Depression was assessed by the Patient Health Questionnaire-9 (PHQ-9), with a score of ≥10 used to indicate possible depression. Results: Data were obtained from 3361 participants. The prevalence of depression was 24% (95% confidence interval [CI] = 11.86 to 39.28) among underweight participants, 11% (95% CI = 8.5 to 14.0) among normal weight participants, 12% (95% CI = 0.9 to 15.2) among overweight participants, and 23% (95% CI = 17.8 to 29.0) among obese participants. The prevalence of depression was higher for women than for men across all weight categories except underweight. Conclusion: Weight and depression demonstrated a U-shaped relationship, with higher prevalence of depression observed among underweight and obese general practice patients. These conditions may act as red flags for opportunistic screening of depression in the general practice setting.