14-05-2025
OCD Linked to Specific Genes, New Study Finds
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A new genetic study of more than 50,000 obsessive-compulsive disorder (OCD) cases has linked around 250 genes to the condition, including more than two dozen identified as likely causal, in about 30 regions of the human genome.
Why It Matters
The study describes obsessive-compulsive disorder as a "chronic psychiatric disorder that affects 1 to 3 percent of the population." Symptoms vary widely in form and severity, with some people experiencing debilitating compulsions that disrupt daily life, while others have milder, more manageable symptoms. Some people diagnosed with OCD experience chronic anxiety, repetitive thoughts, chronic fears and paranoia, among symptoms.
The study claims its findings "substantially advances the field of OCD genetics" due to the identification of new OCD genetic risk loci and multiple credible candidate causal genes.
What To Know
Nearly 200 researchers from universities in Europe, North America, and Australia conducted and published the largest study on OCD in Nature Genetics on May 13. The study marks the most comprehensive understanding of OCD yet, comparing DNA from 53,660 people with OCD to over 2 million people without it.
It identified 30 specific loci where DNA variants are associated with higher susceptibility to OCD, most active in three brain areas: the hippocampus, striatum, and cerebral cortex.
"By looking closely at the identified DNA regions, we pinpointed 249 potential genes involved in OCD and then narrowed this down to 25 particularly strong 'candidate' genes," which are also known as causal genes, "because they can be involved in the process of causing OCD," Marco Galimberti, a lead researcher on the study and an associate research scientist at Yale School of Medicine's Gelernter Lab, told Newsweek.
Stock photo of an illustrative model of a brain on the table next to a young EEG test subject.
Stock photo of an illustrative model of a brain on the table next to a young EEG test subject.
Jacob Schr'ter/picture-alliance/dpa/AP Image
"Some of these causal genes are WDR6, DALRD3 and CTNND1 and multiple genes in the major histocompatibility complex (MHC) region," he added.
The 25 likely causal genes were identified through at least two independent gene-based tests and passed colocalization and other statistical tests, indicating they are likely affected by the same genetic variants that increase the risk for OCD.
The study also found that there is a genetic overlap with OCD and several other psychiatric conditions and disorders, finding, "In particular, OCD shared genetic risk with anxiety, depression, anorexia nervosa and Tourette syndrome and was negatively associated with inflammatory bowel diseases, educational attainment and body mass index."
Galimberti told Newsweek he found this finding "particularly interesting," however, noting that "the relationship between OCD and Tourette syndrome may not be surprising."
What People Are Saying
Professor Eske Derks, senior group leader of the Translational Neurogenomics Laboratory at QIMR Berghofer, said: "This is the first study where we found actual genes that play a role in OCD, which is really found a really large number of genes which are shared with anxiety disorders, depression and also with anorexia nervosa. There's a lot of overlap in the genes that cause these different mental health conditions."
Carol Mathews, chair of the University of Florida's College of Medicine's Department of Psychiatry, said about the study: "When we started early in my career, we were looking for genes that cause OCD. We thought back then that it would be one or two. Over time, we've come to realize that OCD is not a disease of a single gene or specific brain region, but rather it's a disease of circuits and hundreds of genes, which together contribute to the development of the disorder."
Manuel Mattheisen, a Dalhousie University research chair and lead senior author on the paper, said in a press release: "These findings emphasize the need for a comprehensive exploration of the contribution of both common and rare genetic factors, as well as their interplay to OCD risk. Future studies will require ancestrally diverse samples to facilitate the discovery of additional OCD risk variants, understanding that these results may be useful for drug repurposing and yield new, more effective treatments."
Mataix-Cols, professor at the Karolinska Institute in Stockholm, one of the international collaborators, said in the press release: "After decades of fumbling in the dark, we have finally cracked the piñata of OCD genetics. This study required unprecedented international collaboration, and I am proud of Sweden's contribution to this effort."
What Happens Next
Galimberti told Newsweek that the researchers "have not conducted analyses on epigenetics in this work. However, it is likely that epigenetics may play a role on OCD as well as on other psychiatric disorders and behavioral traits."
Studies like this are often used to guide drug development, improve treatment options, and increase research and public awareness.
