Given that the experimental and control rats were raised in the same tightly controlled conditions, the only difference being their brain status, researchers concluded that the integrity of the amygdala was the root cause of both impaired fear behavior and heightened drug response.
Brain conditions may alter addiction vulnerability independently of drug history, says Chambers. He and his colleagues concluded that someones greater vulnerability to addiction, rather than a given drugs ability to alter the symptoms of mental illness for better or worse (usually worse), more fully explains the high rates of dual diagnosis.
For these reasons, and given the lab evidence and the fact that dual diagnosis patients do less well on psychiatric medication than other patients, Chambers wondered whether the underlying problems in the brain what he calls neural inflexibility -- make it harder for these people to respond.
To improve the effectiveness of treatments for dual diagnosis, Chambers would like to see educators, counselors, physicians, and scientific researchers integrate insights into both mental health and addiction. Funding the simultaneous treatment of both disorders would also help, he observes, given that dual-diagnosis cases are the mainstream among these patients, probably because addiction and mental illness are strongly linked by neurobiology.
What may harm the amygdala early in human development" Dr. Chambers cites the relatively rare cases of temporal lobe epilepsy, tumors or early brain injury. Far more common, he speculates, are complex interactions among subtle genetic and environmental factors that change the way the amygdala functions or is connected to the rest of th
|Contact: Pam Willenz|
American Psychological Association