Genetic epidemiology of anxiety disorders.

This chapter reviews the genetic epidemiology of the major subtypes of anxiety disorders including panic disorder, phobic disorders, generalized anxiety disorder, and obsessive-compulsive disorder. Controlled family studies reveal that all of these anxiety subtypes are familial, and twin studies suggest that the familial aggregation is attributable in part to genetic factors. Panic disorder and, its spectrum have the strongest magnitude of familial clustering and genetic underpinnings. Studies of offspring of parents with anxiety disorders an increased risk of mood and anxiety disorders, but there is far less specificity of the manifestations of anxiety in children and young adolescents. Although there has been a plethora of studies designed to identify genes underlying these conditions, to date, no specific genetic loci have been identified and replicated in independent samples.