Study finds ‘strong’ link between obesity and depression

Obesity or being overweight can cause depression even when no other health problems exist, a study released on Tuesday by the University of Exeter reveals.

A team, led by researchers from the University of Exeter and University of South Australia, analysed UK Biobank data from over 48,000 people with depression and compared them with another group of more than 290,000 people.

Jess Tyrrell of University of Exeter Medical School said: “While it has long been known that depression is more common in obesity, the team concluded that higher body mass index (BMI) can cause depression in itself, even in the absence of other health problems.

“Our robust genetic analysis concludes that the psychological impact of being obese is likely to cause depression.

“This is important to help target efforts to reduce depression, which makes it harder for people to adopt healthy lifestyle habits.”

Tyrrell said the team tested their results in a second large-scale cohort, using data from the Psychiatric Genomics Consortium and reached the same conclusion, verifying their results.

Elina Hypponen, who co-led the study, said the team took a genomic approach to their research.

“We separated the psychological component of obesity from the impact of obesity-related health problems using genes associated with higher body mass index (BMI), but with lower risk of diseases like diabetes.

“These genes were just as strongly associated with depression as those genes associated with higher BMI and diabetes. This suggests that being overweight causes depression both with and without related health issues — particularly in women”

The study has been published in the International Journal of Epidemiology.