A small Chinese study suggests that the brains of teenagers who are seemingly addicted to the internet have abnormal "white matter," the biological insulation that surrounds the wiring between neurons.
It's not clear if this difference could cause internet addiction or actually be caused by it. And the research doesn't point to a treatment or cure for internet addiction, a controversial diagnosis that the mental health community hasn't universally accepted.
Still, the research makes sense because of the regions of the brain in question, said Jonathan Wallis, an associate professor of psychology and neuroscience at the University of California, Berkeley, who studies the brain and is familiar with the new findings.
"The areas that they (the study authors) have pinpointed are ones that we already know are involved in addiction and compulsive behaviour," he said. The differences in white matter in the subjects described as Internet addicts is "the kind of impairment that we'd expect to disrupt the normal function of those areas."
Topic of debate
The existence of internet addiction is a widely debated issue in the world of mental health, especially since the main handbook of psychological disorders - the Diagnostic and Statistical Manual of Mental Disorders - is undergoing revision. Among other things, specialists disagree over whether the condition is truly an addiction or fits into another category.
Internet addiction has been an especially hot topic in China, where researchers at Jiao Tong University and the Chinese Academy of Sciences launched the new study.
The researchers gave MRI brain scans to 17 adolescents who appeared to suffer from internet addiction. Among other things, the teens said they were preoccupied with the Internet, had repeatedly tried to control their use without success, and felt restless, moody, depressed or irritable when they tried to cut down.
The researchers compared their brain scans to those of 16 "healthy" teens of the same ages and genders.
Affects on decision-making
The scientists found that those teens who appeared to have internet addiction had impaired "white matter" connecting the parts of their brains that deal with issues like decision-making.
White matter refers to the insulation that envelops the wiring that connects brain cells called neurons, Wallis said. "They're connected along the biological equivalent of wire. Just like in any piece of electrical equipment, you want insulation around those wires. The neurons lay down fat, which stops the electrical charge from leaking out of the neuron."
So which came first, the damage to the insulation or the addiction itself? "We don't know whether the poor insulation connecting these areas of the brain predisposes these people to developing compulsive behaviours or whether engaging in a behaviour repetitively could damage the connections between brain areas," Wallis said.
One possible theory is that the faulty insulation disrupts communication in the brain to the point where a person thinks a behaviour is valuable and should be repeated over and over again, Wallis said. That, he added, may be a key to addictions of various types.
The research offers more insight into how some people may be more prone to addiction because of the way their brains work, said Gordon Harris, a professor of radiology at Harvard Medical School who is studying alcoholism and the brain.
"It's not just a personal failing or weakness," Harris said.
The new study findings appear in an issue of the journal PLoS One.
(Copyright © 2011 HealthDay. All rights reserved.)