Identifying which teens might be at the highest risk for developing a substance use disorder is dependent on a combination of genetic and environmental factors. However, if such a strategy could be implemented, high risk teens could be targeted for specialized education and early intervention programs.
A recent study conducted by Eric Stice and colleagues at the Oregon Research Institute provides important clues about how the brain works in an adolescent who is more likely to develop a substance use problem.
The findings, which appear in the journal Biological Psychiatry, show that overactivity in the part of the brain the processes rewards may lead to increased cravings when drugs are introduced. The research was conducted through the use of a “reward surfeit model” to determine whether an increased level of activity in the reward center is followed by strong food or drug addiction.
The researchers found that when there was an elevated level of response in the brain’s reward regions, the individual was at an increased risk for substance use in the future. However, the findings also support that even minimal substance use can result in a lower level of response in the reward center.
The study relied on the use of fMRI scans to determine whether excessive weight gain could be predicted by the responsivity in the reward region of the brain. In addition, the researchers tested whether abstinent adolescents’ levels of responsivity would predict their substance use.
The researchers tested the 162 participants’ responses to food and monetary rewards. The adolescents were measured for body fat and evaluated for substance use at the time that the fMRI was conducted. The adolescents were evaluated again one year later.
Stice explained that the findings provide important information because this study is the first to provide evidence that atypical responsibility is a predictor for substance use in adolescents.
The researchers examined the response of the reward circuitry to various tasks in which the receipt of money or the expected receipt of money was the reward. The researchers also evaluated the rewards system as it responded to the anticipation and consumption of a chocolate milk shake.
The adolescents who exhibited a stronger activation in a section of the brain referred to as the striatum during the receipt of monetary rewards were more likely to initiate substance use before the one-year follow up meeting.
In addition, the researchers found that adolescents who had already initiated substance use exhibited a lesser response in the reward circuitry when monetary reward was involved.
The conclusion implied by the results is that as an adolescent begins to use substances and continually increases use, the less responsive they will be when other types of rewards are introduced. These rewards may include academic achievements or personal relationships. The connection may explain the coinciding increase of drug use with the decline of all other interests in the typical addict.