From Yale University
Blood flow to the brain indicates when recovering cocaine addicts are able to benefit from talk therapy
New Haven, Conn. – Measuring blood flow to the brain may be a useful way to determine when a recovering cocaine addict is able to benefit from cognitive behavior therapy as a treatment for cocaine addiction, a Yale researcher has found.
Cocaine constricts coronary and cerebral blood vessels, but the consequences on brain function until now have been unclear, said Christopher Gottschalk, M.D., assistant professor of psychiatry and neurology at Yale School of Medicine and lead author of the study published in the April issue of the American Journal of Psychiatry.
"Although prior studies have indicated that the severity of these flow deficits is related to the degree and duration of drug abuse, their pathophysiology is unknown, and their consequences on brain function are unclear," he said.
To determine the effects on brain function, Gottschalk and his colleagues measured the cerebral perfusion, or blood flow, of two women – Ms. A and Ms. B -- twice over the course of their participation in a 28-day treatment program for cocaine addiction. The women also underwent neuropsychological testing to measure their ability to perform certain tasks.
The study, supported by grants from the National Institute on Drug Abuse, measured cerebral perfusion using single photon emission computer tomography (SPECT).
"Ms. A was better prepared, psychologically, for taking control of her behavior, and Ms. A benefited to a significant degree from the education offered in treatment," the researchers said in the study. "The second patient, Ms. B, began treatment far less prepared to make any meaningful progress in her recovery … but made significant advances in her level of insight and ability to make inferences about her behavior in relation to her thoughts and reactions. We hypothesize that this difference in cognitive flexibility is, in part, a reflection of the state of cerebral function during the period of treatment and that cerebral perfusion can provide a useful measure of this state."
Gottschalk said measuring the cerebral perfusion of cocaine addicts in treatment is critical because cognitive behavior therapy relies on changing behavior and affective responses by teaching coping skills and by addressing and modifying dysfunctional thought patterns.
Most substance abuse programs include education about addiction, anger management, and motivational enhancement in both individual and group settings to provide alternative responses when an addict is faced with unmanageable feelings, urges or circumstances.
"The capacity to respond to such ‘psychosocial’ intervention is largely dependent on a patient’s cognitive flexibility," Gottschalk said. "We predicted the change from baseline perfusion would correlate with a measure of the capacity to learn new behavior. We found evidence to support this idea in the two cases presented."
Among the areas that showed marked decreased perfusion, he said, were several cortical regions.
The other researchers on the study were John Beauvais, clinical instructor, psychiatry; Rachel Hart, addiction therapist, psychiatry; and Thomas Kosten, M.D., professor of psychiatry.