The Intergenerational Transmission of Anxiety Disorders and Major Depression

Depression and anxiety disorders are the most common mental illnesses. They cluster within families, often co-occur, and cross predict each other (1-3). Depression or anxiety in a parent is common and increases the risk for anxiety and depression and other mental health and functional difficulties in biological offspring (2, 3). Parental anxiety and depression affect large numbers of offspring. For example, a study of health records from England estimated that 26% of children aged 0-16 had a mother with an anxiety disorder or major depressive disorder diagnosed by a health care professional (4). A separate U.K. study focusing on offspring aged 0-30 reported a higher prevalence, with depression affecting 34.5% of mothers and 18.0% of fathers (5). Understanding the factors that underlie how anxiety and depression are transmitted within families is therefore important and informs prevention and early intervention strategies, including public health strategy. To address the question of how anxiety and depression are transmitted within families, genetically informed, familybased designs can separate the relative contribution of ge