Though it is known that depression is more common in people who are obese, new studies using UK Biobank data are the first to conclude that higher BMI can cause depression in itself, even where no other health problems exist. The genetics study, a collaboration between researchers in Exeter and Australia, suggests that it is the psychological impact of being overweight that causes depression, rather than associated illnesses. This furthers understanding of the complex relationship between obesity and depression. It will help experts develop new ways to tackle the obesity epidemic. The team tested their results in a second large-scale cohort, using data from the Psychiatric Genomics Consortium, where they reached the same conclusion.