Drug addiction-are you born that way, do you acquire it somehow or is it thrust upon you? The question, which has baffled neuroscientists for so long , may have some sort of an answer now-at least for rat junkies.
Scientists working for the Behavioral and Clinical Neuroscience Institute, UK, conducted a study on lab rats to test out the notion.
It has long been known that drug addicts have a paucity or shortage of dopamine receptors- areas of the brain that are latched upon by drugs such as cocaine and heroin, to produce their effect.
Impulsiveness or excessive sensation seeking behavior has been previously linked to drug addiction in humans. Researchers agree that drug addiction and excessive sensation seeking, or impulsivity, are linked but it has been unclear (at least till, now)- which comes first impulsivity or drug addiction.
The scientists did a simple test to find out which rats out of a batch of them, were impulsive. The impulsive rats were then introduced to drugs. It was seen, several brain scans later, that those rats, which were more impulsive, took drugs more often, and that those rats did have a lesser number of dopamine receptors than the others.
The researchers who published their finding in Science, say they could rightly conclude that those rats, which had a genetically-determined, lesser number of dopamine receptors, were more addicted to drugs. Hence the conclusion here, that drug addiction could be considered genetically determined.
Says lead author Jeff Dalley, " What we are talking about here is a possible physical trait producing vulnerability to drug use.
"The next step is identifying the gene or genes that cause this diminished supply of brain receptors.
"This may provide important new leads in the search for improved therapies for attention deficit, hyperactivity disorder (ADHD) and compulsive brain disorders such as drug addiction."
The findings may lead to more targeted treatments for addiction and other compulsive behavior disorders with fewer side effects than current options, opine the researchers.