(HealthDay News) – Distinct networks are associated with the impulsivity exhibited by adolescents who use drugs or have attention-deficit/hyperactivity disorder (ADHD).

Robert Whelan, PhD, from the University of Vermont in Burlington, and colleagues used functional magnetic resonance imaging to investigate the brain networks involved in inhibition and inhibition failure in a sample of 1,896 14 year olds.

The researchers found that distinct networks were associated with drug use (1,593 adolescents) and with symptoms of ADHD (342 adolescents). Low functioning of a specific orbitofrontal cortical network was related to the likelihood of initiating drug use early in adolescence. The speed of the inhibition process and illegal substance use correlated with right inferior frontal activity. This activity was also linked with genetic variation in a norepinephrine transporter gene.

“Our results suggest that human adolescent impulsivity can be decomposed into a number of distinct networks and that these networks can be related to different phenotypes and to genetic variation in a gene encoding norepinephrine transporter,” the authors write.

Several authors disclosed financial relationships with pharmaceutical companies.

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