Why one teenager refuses smoking or experimenting with drugs over another?

Scientists behind world’s largest imaging study of the human brain (1,896 14-year-olds) discovered a number of previously unknown networks. These findings help explain the previously unknown mysteries of the mind

University of Vermont’s Robert Whelan and Hugh Garavan, along with a large group of international colleagues, implicate that differences in these networks suggest a strong linkage with teenage-drug use. They explain how some teenagers are at higher risk for drug and alcohol experimentation simply because their brains work differently; making them more impulsive.”These networks are not working as well for some kids as for others,” says Whelan.

Their findings were presented in the journal Nature Neuroscience, published online.

This discovery helps answer a long-standing chicken-or-egg question. Whether certain brain-patterns come before drug use – or are caused by it.

Garavan one of the most esteemed colleagues of Whelan confirms the findings. “The differences in these networks seem to precede drug use,”

Diminished activity in a network involving the “orbitofrontal cortex” is associated with alcohol, cigarettes and illegal drugs experimentation, in early adolescence.

Garavan explains that when faced by an offer to smoke/ drink, the 14-year-old with a less functional impulse-regulating network will say: “yeah, gimme, gimme, gimme!”, and the one with normal impulse regulation will say: “no, I’m not going to do that.”

Garavan hopes that testing for lower function in brain networks could, perhaps, be used by researchers someday as “a risk factor/ biomarker for potential drug use”.

The study further revealed that networks distinct from those of drug-use were associated with symptoms of attention-deficit hyperactivity disorder (ADHD)

There has been plenty controversy and media attention suggesting a possible connection between ADHD and drug abuse. Poor inhibitory control is displayed in both; ADHD and early drug-use. They’re problems that have long plagued impulsive people. This new research, however, negates these seemingly related problems. They are regulated by different networks in the brain. Therefore, the idea that risk of ADHD is not necessarily a full-blown risk for drug use is strengthened. Poor responses on ‘stop-signal reaction time’ tests should not be confused for a sign of linkage between the two diseases.

Whelan and colleagues used the mathematical approach called factor-analysis. They were able to fish out seven networks involved when impulses were successfully inhibited and six networks involved when inhibition failed – from the vast and chaotic actions of a teenage brain at work.

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

However, death among teenagers, especially, in the industrialized world is largely caused by preventable or self-inflicted accidents that off shoot from impulsive-risky behaviors. Alcohol and drug use is common. Garavan admits: “Addiction in the western world is our number one health problem”. Understanding brain networks that put some teenagers at higher risk for starting to use substances could have groundbreaking implications in public health.   By Ammara Hashmi