LONDON: Overweight and obese people may be at increased 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 overweight causes depression instead of associated diseases such as diabetes.
"Our research shows that overweight not only increases the risk of chronic diseases such as cancer and cardiovascular disease, but can also lead to depression," said co-author Elina Hypponen, professor at the University of South Australia.
For the study, the researchers looked at UK Biobank data from more than 48,000 people with depression, compared 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-report were used to determine if people had depression.
The team used a genetic research approach to investigate the causal relationship between the two disorders.
They differentiated the psychological component of obesity from the impact of obesity-related health problems, using genes that are associated with a higher BMI, but with a lower risk of diseases such as diabetes.
"These genes were just as strongly associated with depression as those genes associated with higher BMI and diabetes, which suggests that obesity causes depression with as well as related health problems – especially in women," Hypponen said.
"Our robust genetic analysis concludes that the psychological impact of having obesity is likely to cause depression, this is important to help us focus on reducing depression, making it much more difficult for people to adopt healthy lifestyle habits, said Jess Tyrrell of the University of Exeter Medical School in Great Britain.