Problematic drug use at the age of 16 can be predicted by the way the brain responds to reward anticipation at the age of 14, shows a study published this week in Nature Communications.
Adolescence is a time that is often marked by impulsive and rash decisions and a general search for thrills and novelty. This type of behaviour can be detrimental, as it encourages risky decisions, but can also be beneficial, because it encourages adolescents to discover and explore new opportunities. Generally, this novelty-seeking behaviour is accompanied by activity in a brain network that responds to motivation. However, it is unclear when this activity predicts positive or negative behaviour.
Christian Buchel and colleagues followed 144 novelty-seeking adolescents from the age of 14 to the age of 16. All the participants completed an extensive psychometric evaluation and were also scanned with functional magnetic resonance imaging while they did a task that primed them to anticipate a monetary reward. Results showed that those adolescents who, at age 14, showed reduced neural activity in response to the anticipation of a monetary reward in brain areas associated with motivation, were more likely to develop problematic drug habits at age 16. This neural marker out-predicted more conventional psychometric measures (for example, low conscientiousness), suggesting that it may be a new method for researchers and clinicians to target vulnerable individuals for intervention before the onset of problematic behaviour.