Severe eating disorder ARFID is highly heritable, according to new twin study

Cynthia Bulik, Ph.D., founding director of the UNC Center of Excellence for Eating Disorders, is a senior author on articles published in JAMA Psychiatry.

ARFID is a serious eating disorder that leads to malnutrition and undernutrition. Researchers estimate that 1-5% of the population is affected by eating disorders.

Unlike anorexia, ARFID is not about the patient’s own body experiences or fear of weight gain. Instead, the disease is characterized by avoidance of certain types of food due to sensory discomfort due to the characteristics or appearance of the food, or, for example, fear of choking, food poisoning, anorexia, etc. .

17,000 pairs of twins participated in the study

Researchers at the Karolinska Institutet and the University of North Carolina School of Medicine are now investigating the importance of genetic factors in developing ARFID. A cohort of approximately 17,000 Swedish twins born between 1992 and her 2010 participated in the study. A total of 682 of her ARFID children from age 6 to her 12 could be identified.

Researchers used the twin method to determine the influence of genes and the environment on disease development.

“Identical twins share all genes, and we know that fraternal twins share about half of the genes that differentiate people. If we find that a particular personality trait is more common in a twin pair, it indicates that there is a genetic influence. We can,” said Lisa Dinkler, Ph.D., lead author of the study and a postdoctoral researcher in the Department of Medical Epidemiology and Biostatistics at the Karolinska Institutet.

research is publish online February 1 JAMA PsychiatryDr. Cynthia Bulik, founding director of the Center for Eating Disorders at UNC-Chapel Hill, is the senior author of this article.

Researchers found that the genetic component for developing ARFID is as high as 79%. This means that 79% of the risk of developing ARFID is explained by genetic factors.

“This study suggests that ARFID is highly heritable. The genetic component is higher than other eating disorders and comparable to neuropsychiatric disorders such as autism and ADHD,” Dr. Dinkler said. say.

ARFID is a relatively new diagnostic. In 2013 the disorder was included in the Diagnostic and Statistical Manual of Mental Disorders DSM-5 and this year in the World Health Organization’s diagnostic manual ICD. to be introduced into the system. Diagnosis is therefore not yet an official part of Swedish health and medicine.

I want to investigate the relationship with other pathologies

The next step in Dr. Dinkler’s research is to study the extent to which ARFID is associated with other psychiatric diagnoses such as anxiety, depression, neurodevelopmental disorders and gastrointestinal disorders.

“We will use twin studies to test the extent to which ARFID shares the genetic and environmental factors underlying these diseases,” said Dr. Dinkler.

This study was primarily funded by the Swedish Research Council, the Swedish Mental Health Foundation, the Fredrik and Ingrid Turing Foundation, Lundbeckvonden, NIMH, and the Brain Behavior Research Foundation.

Many researchers are paid by private companies for work done outside of this research. See our scientific article for more information.

Publication: “Pathogenesis of a widespread avoidant-restrictive food intake disorder phenotype in Swedish twins aged 6-12 years”, Lisa Dinkler, Marie Louis Rohnski, Paul Lichtenstein, Sebastian Landström, Henrik Larson, Nadia Mikari, Mark J. Taylor, Cynthia M. Brik, JAMA Psychiatryonline 1 February 2023, doi: 10.1001/jamapsychiatry.2022.4612