BEHAVIORAL AND MENTAL DISORDERS
GENETICS, ADOPTION AND MENTAL HEALTH DISORDERS
Affective Disorders and Adoption
Genetic susceptibility contributes to the expression of depression and bipolar disorders. Adoption studies support this conclusion. However, investigators agree that environmental factors are crucial in modulating disease expression. Heritability of major depression is estimated in the range of 31-42%, although certain subtypes may be higher. Inherited variations in regional brain volume and shape increase susceptibility to depression, although this is not certain. Other factors, such as prenatal alcohol exposure (possibly mediated via postnatal exposure to maternal depression) or early adverse life events (possibly mediated via altered hypothalamic-pituitary axis responsiveness), also contribute to disease expression. Genetic evidence links affective disorders to autism spectrum disorders, conduct disorder, and hyperactivity.
From THE HANDBOOK OF INTERNATIONAL ADOPTION MEDICINE by Laurie C. Miller. © 2004 by Oxford University Press, Inc. Used by Permission.