It’s a common-sense notion that those who have been abused as children may became drug abusers later in life. But why is this so? Carl Anderson, a Harvard instructor in psychiatry and a research associate in McLean Hospital’s Developmental Biopsychiatry Research Laboratory and Brain Imaging Center, and his colleagues investigated. They found that repeated sexual abuse affects the blood flow and function of a key brain region related to substance abuse, the cerebellar vermis. This part of the brain has been recently implicated in the coordination of emotional behavior, is strongly affected by alcohol, cocaine, and other drugs of abuse, and may help regulate dopamine, a neurotransmitter critically involved in addiction. “Damage to this area of the brain may cause an individual to be particularly irritable, and to seek external means, such as drugs or alcohol, to quell this irritability,” said Anderson. Anderson said the team’s findings enhance understanding of the developmental mechanisms of childhood sexual abuse, which may result in new methods of treatment for child-abuse survivors.