Obsessive-Compulsive Disorder and Its Cross-Generational Familial Association With Anxiety Disorders in a National Swedish Extended Adoption Study

This Swedish population register-based study found that OCD was transmitted from parents to children largely through a genetic relationship, with rearing playing a minor role. Viewed cross-generationally, OCD and anxiety disorders were moderately genetically correlated, with the genetic correlations strongest between OCD and GAD, intermediate for OCD and social phobia, and weakest between OCD and panic disorder. These genetic correlations were modestly attenuated when diagnostic hierarchies were imposed before analysis.