Genetic aspects of obsessive-compulsive disorder.

Developments in molecular genetic methods have proved to be powerful tools in the search for genes involved in complex diseases, and they hold the promise of understanding the genetic basis of OCD. The next step in understanding the genetics of OCD is the localization and characterization of the genes that confer susceptibility. A more complete understanding of the genetic basis of OCD and of the interactions between relevant genotypes and relevant environmental factors is important for clarification of the cause, pathogenesis, and treatment of this complex disorder. These genetic methods must be combined with careful clinical and epidemiologic work to correctly elucidate the cause of OCD. Future research also should define subsets of endophenotypes of the disorder. Factors such as neuropsychological functioning, personality testing, comorbidity, and age of onset are extremely useful in the continued study of genetic mechanisms involved in the cause of OCD.