Biological Links Found Between Childhood Abuse and Adolescent Depression - ScienceDaily (Apr. 20, 2011)
Kate Harkness has found that a history of physical, sexual or emotional abuse in childhood substantially increases the risk of depression in adolescence by altering a person's neuroendocrine response to stress. Adolescents with a history of maltreatment and a mild level of depression were found to release much more of the stress hormone cortisol than is normal in response to psychological stressors such as giving a speech or solving a difficult arithmetic test.
"This kind of reaction is a problem because cortisol kills cells in areas of the brain that control memory and emotion regulation," explains Dr. Harkness, a professor in the Department of Psychology and an expert in the role of stress and trauma in adolescent depression. "Over time cortisol levels can build up and increase a person's risk for more severe endocrine impairment and more severe depression."....
Dr. Harkness recently presented her findings at the International Society for Affective Disorders Conference in Toronto. http://www.sciencedaily.com/releases/2011/04/110420125506.htm