Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Huge study finds brain networks connected to teen drug abuse

30.04.2012
Why do some teenagers start smoking or experimenting with drugs—while others don't?

In the largest imaging study of the human brain ever conducted—involving 1,896 14-year-olds—scientists have discovered a number of previously unknown networks that go a long way toward an answer.


Newly discovered networks in the brain, shown here in color, go a long way toward explaining why some teenagers are more likely to start experimenting with drugs and alcohol. Diminished activity in some of these networks, discovered by two scientists at the University of Vermont and their European colleagues, makes some teens more impulsive -- and less able to inhibit urges to try alcohol, cigarettes and illegal drugs in early adolescence.

Credit: Robert Whelan, University of Vermont, Nature Neuroscience, 2012

Robert Whelan and Hugh Garavan of the University of Vermont, along with a large group of international colleagues, report that differences in these networks provide strong evidence that some teenagers are at higher risk for drug and alcohol experimentation—simply because their brains work differently, making them more impulsive.

Their findings are presented in the journal Nature Neuroscience, published online April 29, 2012.

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

"The differences in these networks seem to precede drug use," says Garavan, Whelan's colleague in UVM's psychiatry department, who also served as the principal investigator of the Irish component of a large European research project, called IMAGEN, that gathered the data about the teens in the new study.

In a key finding, diminished activity in a network involving the "orbitofrontal cortex" is associated with experimentation with alcohol, cigarettes and illegal drugs in early adolescence.

"These networks are not working as well for some kids as for others," says Whelan, making them more impulsive.

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!" says Garavan, "and this other kid is saying, 'no, I'm not going to do that.'"

Testing for lower function in this and other brain networks could, perhaps, be used by researchers someday as "a risk factor or biomarker for potential drug use," Garavan says.

The researchers were also able to show that other newly discovered networks are connected with the symptoms of attention-deficit hyperactivity disorder. These ADHD networks are distinct from those associated with early drug use.

In recent years, there has been controversy and extensive media attention about the possible connection between ADHD and drug abuse. Both ADHD and early drug use are associated with poor inhibitory control—they're problems that plague impulsive people.

But the new research shows that these seemingly related problems are regulated by different networks in the brain—even though both groups of teens can score poorly on tests of their "stop-signal reaction time," a standard measure of overall inhibitory control used in this study and other similar ones. This strengthens the idea that risk of ADHD is not necessarily a full-blown risk for drug use as some recent studies suggest.

The impulsivity networks—connected areas of activity in the brain revealed by increased blood flow—begin to paint a more nuanced portrait of the neurobiology underlying the patchwork of attributes and behaviors that psychologists call impulsivity—as well as the capacity to put brakes on these impulses, a set of skills sometimes called inhibitory control.

Edythe London, Professor of Addiction Studies and Director of the UCLA Laboratory of Molecular Pharmacology, who was not part of the new study, described it as "outstanding," noting that the work by Whelan and others "substantially advances our understanding of the neural circuitry that governs inhibitory control in the adolescent brain."

Using a complex mathematical approach called factor analysis, Whelan and colleagues 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. These networks "light up," Whelan says, in a functional MRI scanner during trials when the teenagers were asked to perform a repetitive task that involved pushing a button on a keyboard, but then were able to successfully stop—or inhibit—the act of pushing the button in mid-action. Those teens with better inhibitory control were able to succeed at this task faster.

But the underlying networks behind these tasks could not have been detectable in a "typical fMRI study of about 16 or 20 people," says Whelan. "This study was orders of magnitude bigger, which lets us overcome much of the randomness and noise—and find the brain regions that actually vary together."

"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.

The new study draws on the multi-year work of the IMAGEN Consortium, funded by the European Union, and headed by Prof. Gunter Schumann at the Institute of Psychiatry, King's College London. IMAGEN, lead by a team of scientists across Europe, carried out neuroimaging, genetic and behavioral analyses in 2000 teenage volunteers in Ireland, England, France, and Germany and will be following them for several years, investigating the roots of risk-taking behavior and mental health in teenagers.

That teenagers push against boundaries—and sometimes take risks—is as predictable as the sunrise. It happens in all cultures and even across all mammal species: adolescence is a time to test limits and develop independence.

But death among teenagers in the industrialized world is largely caused by preventable or self-inflicted accidents that are often launched by impulsive risky behaviors, often associated with alcohol and drug use. Additionally, "addiction in the western world is our number one health problem," says Garavan. "Think about alcohol, cigarettes or harder drugs and all the consequences that has in society for people's health." Understanding brain networks that put some teenagers at higher risk for starting to use them could have large implications for public health.

Joshua Brown | EurekAlert!
Further information:
http://www.uvm.edu

More articles from Studies and Analyses:

nachricht Real-time feedback helps save energy and water
08.02.2017 | Otto-Friedrich-Universität Bamberg

nachricht The Great Unknown: Risk-Taking Behavior in Adolescents
19.01.2017 | Max-Planck-Institut für Bildungsforschung

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>