Researchers at the University of California San Diego School of Medicine have detected abnormal neural activity in the parts of the brain that are activated with anticipatory functions in young occasional users – 18 to 24 years old – of stimulant drugs such as cocaine or amphetamines.
Using functional magnetic resonance imaging (fMRi), the scientists found brain differences that could be due to increased stiffness in neural connections and possibly make them more likely to be addicted in the future.
One of the possible applications of the study, published in the Journal of Neuroscience, would be to use patterns of brain activity to identify the risk of consumption among young people long before signs of addictive behavior appear.
“If they show me a sample of 100 university students and point out who have taken stimulants twelve or fifteen times, I could assure that their brains will present differences compared to those of those who have not tried them. The study does not tell us’ this is your brain with drugs ‘, but’ this is the brain that drugs build , “says Martin Paulus, professor of Psychiatry and one of the co-authors of the work with Angela Yu, professor of Cognitive Sciences at UC San Diego.
In the experiment, the reaction capacity of the young participants was tested when it came to pressing either the left or the right button depending on whether an X or an O appeared on a screen, or not pressing it if a beep sounded. Reaction times and their successes and errors were measured after 288 attempts, while brain activity was scanned by fMRI.
Occasional users showed slightly faster reaction times, suggesting a tendency to impulsivity. However, the most notable difference between one and the other occurred in the stop runs (when the beep sounded and they did not have to do anything).
On these occasions, drug users made more mistakes and their performance worsened as the test became more complicated , for example when the beep was delayed. Correlatively, the brain images of these experiment volunteers showed a decrease in neuronal activity in the areas of the brain related to anticipation functions.
“We thought that drug addicts had willpower problems, but the study indicates that the root of drug addiction can come from a dysfunction when it comes to anticipating situations and detecting when to stop,” says Katia Harlé, lead author of the research .
The next step will be to examine to what extent these patterns of brain activity are permanent or if it is possible to recalibrate them by exercising the weakest areas, where the slowdown in neural activity is associated with a greater tendency to addiction. There are currently no effective treatments for stimulant addiction, so prevention is the best option , according to Martin Paulus.
