 This systematic review has examined the existing literature on the association between obesity and various psychiatric disorders. It found that there is strong evidence of a bi-directional relationship between depression and obesity, with longitudinal studies showing a higher likelihood of developing depression in individuals who are obese compared to those who are not. Cross-sectional studies showed a similar trend, although the ORS was slightly lower. There was also some evidence of a bi-directional relationship between anxiety disorders and obesity, although the ORS were much lower than those seen for depression. Additionally, there was limited evidence of a link between obesity and other psychiatric disorders such as personality disorders, eating disorders, ADHD, and alcohol use. This article was authored by T. M. Rajan and V. Menon.