The co-morbidity of anxiety and depression in the perspective of genetic epidemiology. A review of twin and family studies.
The authors report data from a case-control family study of lifetime psychiatric diagnoses among the relatives of individuals with major depression. Specifically, they address the relationship between anxiety disorders and major depression. The findings indicate that relatives of individuals with major depression plus an anxiety disorder are at greater risk for major depression, as well as anxiety disorders; than are the relatives of individuals with major depression without an anxiety disorder. This increased risk appears to be present whether or not the anxiety disorder occurs solely in association with episodes of major depression or is temporally separate. The nosological implications of these findings are discussed.