Faculty of Medicine

ADHD and obesity share genetic ground

Persons with ADHD have three times higher risk of obesity than others and the two conditions are caused by the same genetic underpinnings, a family study suggests.

ADHD and clinical obesity have familial causes.

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Researchers have known for a while that people with ADHD are at increased risk for obesity. A new EU-study replicates that risk and shows that it also extends to family members. This suggests that the link is due to share familial causes between the disorders.

“The study shows that the association between ADHD and clinical obesity in adolescence and young adulthood can be partly attributed to the genetic underpinnings shared by the two conditions,” Stephen Faraone, Professor II at K.G. Jebsen Centre for Neuropsychiatric Disorders at University of Bergen, and Distinguished Professor of Psychiatry, SUNY Upstate Medical University, New York, USA.

The study is published in Psychological Medicine

Comparing family members

By comparing the risk of clinical obesity with persons with ADHD and their siblings and cousins, the researchers could examine whether the link is caused by genetic or environmental factors.

“The relative contributions of genetic and environmental factors to the association between ADHD and clinical obesity were examined,” Faraone says.

The researchers identified 25 38 127 individuals born between 1973 and 2000 from the Swedish national registers, together with their siblings and cousins.

Hunting causation in EU-project

The study is a part of the EU CoCA project, where the researchers are trying to understand why ADHD co-occur with many disorders, including obesity. 

“If we can better understand the nature of the co-occurrence and its causation, we can develop better treatments.“

– Should be monitored

The individuals with ADHD had 3 to 4 times higher risk of clinical obesity compared with those without. Knowing that ADHD youth are at risk for obesity is also important for healthcare professionals so that they can monitor their ADHD patients and try to prevent obesity before it occurs.

“Children with ADHD should be monitored for weight gain so that preventive measures can be taken when in example the children begin to show some signs of being overweight,” says Stephen Faraone.