Biological factors moderate the risk of eating disorders in adolescents

“We know that, like many other mental health conditions, rates of eating disorders increase in adolescence, and that may be related to both changes in the way the brain develops during this period and genetic factors,” said lead author Margaret Westwater. Laboratory partner and former colleague after Yale School of Medicine.

“But we don’t fully understand the ways in which genetic risk or brain structure may influence your risk of eating disorders, especially during critical periods of development.

Westwater is part of the lab of Yale’s Dustin Scheinost, associate professor of radiology and biomedical imaging and co-author of the study.

To better understand what biological factors may play when it comes to the development of eating disorders, the research team used data from the National Institutes of Health’s Adolescent Brain and Cognitive Development Study, the largest long-term study of brain development and child health. United States. They examined genetic risk, cognitive structure, and eating disorder symptoms in more than 4,900 youth ages 9 to 11.

They found that the genetic risk of high body mass index (BMI) was associated with symptoms of an eating disorder, but not symptoms of anxiety, depression, or obsessive-compulsive disorder.

““That was a little surprising because there is evidence in adults that a genetic risk of high BMI is associated with depression, but that’s not what we found in this small group,” Westwater said.

Researchers have found that genetic risk factors for BMI and anorexia are associated with different brain structures. In particular, high BMI risk is associated with greater cortical thickness in certain brain regions and extensive reduction in brain area while anorexia risks are associated with reduced caudate volume. The caudate, which lies deep in the brain, is associated with motor control and higher level cognition such as learning and decision making.

“We know from previous research that there is likely to be something going on in the pathogenesis of anorexia nervosa,” said Westwater. But here we find a link in children with a high genetic risk of anorexia, but who do not have anorexia itself. It may suggest that the reduction of the volume of the caudate may be a risk factor of transfer to this disease.”

In addition, the research team found that symptoms of eating disorders are associated with a greater size of the visual brain network and a decrease in the complexity of the active brain network when the person is in a more relaxed state and not focused on their external environment.

““Patients with eating disorders have disturbing thoughts about the body or food,” says Westwater. “So it’s possible that some fundamental difference in the structure of the brain’s network contributes to those characteristics.”

One of the biggest takeaways from the findings, he added, is that biological factors shape the development of eating disorders at a very young age.

“While we have recognized for a long time that eating disorders appear during adolescence, this is one of the first pieces of evidence showing that there are genetic and neurobiological mechanisms modulating a person’s risk of these conditions at the age of 10, which is much earlier. than most people associate with an eating disorder,” said Westwater. “It emphasizes the need for screening in schools and primary care settings and for early intervention to save people years of suffering.”

The study was conducted in collaboration with researchers at the National Institute of Mental Health, Harvard Medical School, the University of Cambridge, and the University of Pennsylvania.