The concept of adiposity-driven inflammation in depression is supported by exemplar evidence from a cohort study that levels of C-reactive protein (CRP), which are indicative of systemic inflammation, account for approximately 20% of obesity-related longitudinal increases in depression scores (9), and that following gastric bypass surgery for patients with obesity, reductions in inflammatory markers CRP and interleukin-6 accompany weight loss and correlate with improved depressive symptoms (10). The gene discussed is CRP; the disease is obesity due to melanocortin 4 receptor deficiency.