Brain Activity Could Identify Youth at Risk for Stimulant Drugs
The study by researchers at the University of California San Diego School of Medicine recruited college students ages 18-24 who were occasional users of cocaine, Adderall or amphetamines, as well as a control group that had never used these kinds of drugs. (Occasional was defined as an average of 12-15 times.) Both groups were screened for conditions such as mental illness or alcohol abuse which might skew the results.
Each student was shown a series of 288 pictures and asked to perform a flexibility task. While viewing a screen, students saw an X or O and were instructed to push a button on their left each time they saw an X and a button on their right if they saw an O. If students heard a tone they were told to not press any button. They were all asked to perform these tasks as rapidly as possible. Brain activity was monitored throughout the series of trials via functional magnetic resonance imaging (fMRI), and their errors and reaction times were also recorded.
The occasional drug using students had marginally quicker reaction times compared to the control group, but they were less able to refrain from button pushing when the tone was sounded. Taken together researchers feel these results point to a greater degree of impulsivity.
The fMRI results showed that anticipatory function was slightly impaired in the brains of the occasional users. The drug-using students were therefore less able to adapt their responses based on what they had learned through previous tasks.
Study author Dr. Martin Paulus says the study gives a picture of what the addict-prone brain looks like before drug use, and that young people who have experimented with stimulants just a dozen times are wired differently.
The fMRIs for occasional users revealed problems in the part of the brain associated with anticipatory function. The unique wiring may lead people to be more susceptible to drug addiction. If the conclusions are correct, it could be possible to detect at-risk youth with a simple brain scan. If it were possible to target prevention efforts before any signs of drug use, the outcomes could be dramatic.
Furthermore, if scientists can pinpoint brain weaknesses associated with addiction, then it may be possible to retrain the area with specific brain exercises. This could help prevent young people from becoming addicted to stimulants, but it could also be used in recovery programs. Right now people addicted to stimulants face a 50 percent relapse rate. But if brain wiring is part of the problem, then brain exercises could perhaps increase the sobriety rates.