The link between obesity and depression may not be as strong as previously thought, suggests research from McMaster University. According to the study, the gene FTO, which is known to be a major contributor to obesity, has been also linked to an 8 percent reduction in an individual’s risk for depression.
“The difference of eight percent is modest and it won’t make a big difference in the day-to-day care of patients,” senior author David Meyre, associate professor in clinical epidemiology and biostatistics at the Michael G. DeGroote School of Medicine and a Canada Research Chair in genetic epidemiology, said in a statement. “But, we have discovered a novel molecular basis for depression.”
Obesity and depression
Meyre and his team pulled data from the larger EpiDREAM study led by the Population Health Research Institute. Information regarding the genetic and psychiatric status of more than 17,000 individuals was analyzed, with DNA samples coming from 21 different countries. The results indicated patients previously found to have the genetic variant FTO also had an 8 percent decreased risk for depression.
The finding opposed what researchers had expected. “We set out to follow a different path, starting from the hypothesis that both depression and obesity deal with brain activity,” said Meyre. “We hypothesized that obesity genes may be linked to depression.”
Previous research has indicated that not only are obese people more likely to be depressed, but depressed people are more likely to become obese.
The research, conducted by Sarah M. Markowitz, M.S., found people who are depressed are more likely to become obese because of physiological changes in hormones and the immune system, and people who are obese are likely to become depressed because of poor health, self-esteem and dissatisfaction with appearance.
“The treatment of depression and obesity should be integrated,” the authors concluded in a statement. “This way, healthcare providers are working together to treat both conditions, rather than each in isolation.”
While evidence indicates being obese may lead to depression, genetically, FTO is still associated with a lower risk for the mental state, which may explain why some overweight individuals are optimistic despite poor health and poor self-esteem.