On Aug. 31, 2026, a Rutgers-led international collaboration has identified 36 genes that substantially raise the risk for obsessive-compulsive disorder (OCD) and chronic tic disorders – providing what two researchers said is the most detailed biological understanding of how these conditions develop – and how they might eventually be treated. Before this study, published in Nature Neuroscience, scientists had found a few genetic clues, each linked separately to OCD or chronic tic disorders. 

OCD is characterized by persistent intrusive thoughts and repetitive behaviors, while chronic tic disorders, including Tourette syndrome, involve sudden, repeated movements or vocalizations that are difficult to control. Together, the conditions affect millions worldwide, often beginning in childhood, and frequently co-occur within the same individuals and families, according to the National Institutes of Health.

The study analyzed DNA from nearly 4,000 people diagnosed with OCD, chronic tic disorders such as Tourette syndrome or both conditions. Researchers focused on rare mutations that disrupt genes that help build and operate the brain. Many of the newly identified genes are shared between OCD and chronic tic disorders.

The findings help explain why the conditions often occur together in the same people and families. At the biological level, the disorders appear to involve many of the same brain pathways.

The researchers also found several of the newly identified genes were previously linked to autism and schizophrenia, reinforcing increasing evidence that multiple psychiatric conditions may stem from related disruptions in brain development and communication.

Brain cells communicate using chemical signals called neurotransmitters that carry messages from one nerve cell to another. The genes identified in the study appear to influence how those signals move through the brain’s circuitry.

By revealing the biological systems behind the disorders, the findings could help scientists design drugs that target the underlying mechanisms rather than simply managing symptoms. The researchers said their study also provides new insight into where these processes occur in the brain. Analyses of gene activity suggest many of the risk genes are active in regions involved in movement, decision-making and habit formation, including parts of the cortex and striatum.