Researchers have identified 36 genes that substantially increase the risk of developing obsessive-compulsive disorder (OCD) and chronic tic disorders (CTDs), including Tourette syndrome. Published in Nature Neuroscience, the study analyzed exome data from nearly 4,000 individuals, including over 2,400 parent-child trios, nearly doubling previous sample sizes. The identified genes carry very large effects, increasing risk by an average of 57-fold and up to 210-fold at the extreme end. Notably, 30 of the 36 genes were associated with both OCD and CTD, confirming substantial genetic overlap between these conditions.