Researchers find teen drug abuse risk marker in brain

Teenagers are impulsive. Period. It's always been the same--in 10 B.C., Horace cited an old man who was always blaming "the youth of today." However, in some teens (but not others) this impulsivity shows itself in dangerous behaviors such as drinking, smoking, or using drugs. Research published in Nature Neuroscience has pinpointed differences in neural networks in the brain that could be used as a biomarker to pick out these at-risk teens, and could allow doctors and others to support them and their families.

The results come from the IMAGEN study, an EU-funded imaging study that looked at the brains of 1,896 14-year olds in England, France, Ireland and Germany. According to the researchers, this is the biggest imaging study of the brain ever carried out. The study found lower activity in networks in the orbitofrontal cortex, part of the frontal lobes of the brain, in the teenagers who were more likely to experiment with alcohol, cigarettes or illegal drugs.

"The differences in these networks seem to precede drug use," said Hugh Garavan of the University of Vermont. "Faced with a choice about smoking or drinking, the 14-year-old with a less functional impulse-regulating network will be more likely to say, 'Yeah, gimme, gimme, gimme!'" said Garavan, "and this other kid is saying, 'No, I'm not going to do that.'"

The study has also linked changes in other brain networks with attention-deficit hyperactivity disorder (ADHD). However, despite speculation about the links between ADHD and drug abuse, this research has shown that different networks regulate the two issues.

"The take-home message is that impulsivity can be decomposed, broken down into different brain regions," Garavan said, "and the functioning of one region is related to ADHD symptoms, while the functioning of other regions is related to drug use."

Addiction is a huge problem worldwide, and accidental deaths in teenagers can often be linked to alcohol and drug use. Tests for lower function in parts of the brain linked with impulsivity could be used as a biomarker to spot the teenagers at higher risk of drug abuse. While drug use and addiction is also correlated with education and upbringing, knowing who is at the greatest risk could direct scarce and expensive resources to protect, support and educate vulnerable children and families.

- read the press release
- see the abstract