Researchers Find Clues Linking Child Abuse to Addiction
Originally published in Alcoholism & Drug Abuse Weekly 14(2), 2002
A five-year study conducted by researchers at McLean Hospital in Belmont, Mass., is providing a better understanding of the link between child physical and sexual abuse and subsequent substance abuse by victims.
Carl Anderson, Ph.D., research associate in McLean's Developmental Psychiatry Research Laboratory and Brain Imaging Center, and colleagues found that repeated sexual abuse affects the blood flow and function of a key brain region related to substance abuse, the cerebellar vermis.
In other studies, this part of the brain has been found to affect the coordination of emotional behavior and to be strongly affected by alcohol, cocaine and other drugs of abuse.
This part of the brain may also regulate dopamine, a neurotransmitter critically involved in addiction.
"Damage to this part 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. The cerebellar vermis plays an important role in infant development.
The researchers analyzed 32 subjects, ages 18 to 22; 15 had a history of childhood abuse, while 17 were controls. According to the researchers, the study results suggest that childhood abuse impaired the development of the cerebellar vermis and left people less able to regulate and control irritability in their limbic system.
Anderson and colleagues also found in a sample of 537 college students that those who frequently abused drugs had higher limbic irritability than those who did not. These students also had higher levels of depression and anger.
Combing data from the two studies, Anderson and his colleagues concluded that childhood abuse impairs the development of the cerebellar vermis, one function of which is to control and limit irritability in the limbic system. These individuals are more likely to use drugs to compensate for this deficiency.
Anderson said the study's findings enhance understanding of the developmental mechanisms of childhood sexual abuse, which may result in new treatments for child-abuse survivors.
