A British and Australian study has unveiled a genetic link between obesity and depression. According to the team, people predisposed genetically to obesity would be more at risk of depressive syndromes. The excessive weight would in fact cause a strong psychological distress, which in some cases also leads to depression.
The link between obesity and depression was already known. But the experts were discussing which of the two disorders is the cause of the other. Is depression causing unhealthy relationships with food or vice versa? To solve this question, an international team analyzed the medical records and DNA of over 500 thousand people.
The scientists examined 73 genetic variants linked to a high body mass index, diabetes and heart disease. To these have added 14 other variants, linked only to obesity and not to other diseases. They then examined the link between genetic variants, health conditions and mental health. The first 73 genetic variants appear to have a biological and psychological link with depression. The other 14 instead have a psychological connection only.
With 4.7 points of body mass index plus there is 18% more chance of developing depression. In the case of women, the percentage rises to 23%. There is therefore a link between genetic predisposition to obesity and depression. Scholars can not say how much this link is psychological in nature and how much of a physiological nature. It seems clear, however, that losing weight also improves mental health, at least in some individuals.