LONDON (Reuters) – Overweight and obese people may be at a higher risk of depression, even in the absence of other health problems, new research warns.
The research, published in the International Journal of Epidemiology, showed that the psychological impact of being overweight causes depression, rather than associated diseases such as diabetes.
"Our research shows that overweight not only increases the risks of chronic diseases such as cancer and cardiovascular disease, it can also lead to depression," said study co-author Elina Hypponen, a professor at the University of South Australia.
For the study, the researchers analyzed data from the UK Bioban of more than 48,000 people with depression, comparing them with a control group of more than 290,000 people born between 1938 and 1971 who provided medical and genetic information.
Hospital data and self-reporting were used to determine if people had depression.
The team used a genetic research approach to explore the causal link between the two conditions.
They separated the psychological component of obesity from the impact of obesity-related health problems, using genes associated with a higher BMI, but lower risk of diseases such as diabetes.
"These genes were as strongly associated with depression as the genes associated with increased BMI and diabetes. This suggests that overweight causes depression with both health problems and related health problems – especially in women," said Hypponen.
"Our robust genetic analysis concludes that the psychological impact of being obese is likely to cause depression. This is important to help direct efforts to reduce depression, which makes it much harder for people to adopt healthy habits," said Jess Tyrrell of the University. of Exeter Medical School in Great Britain.