Cultureplaces

Physical differences in the brain may increase the chances of a person choosing to take drugs, say Cambridge University scientists. A study of rats showed variations in brain structure pre-dated their first exposure to narcotics, and made them more likely to opt for cocaine. Writing in Science , the team say genes may affect these differences in humans. Treatments to reduce their effect may be found - but a test of vulnerability to drugs is unlikely, they add. Up to 500,000 people are currently addicted to Class A drugs such as cocaine, heroin and amphetamines, according to government figures. One of the most important questions in the science of addiction surrounds the origin of differences noticed in the brains of human drug users. While these differences are thought to be important in the way humans respond to drugs, it is difficult to prove whether they are a part of the natural brain chemistry of that individual, or have developed as a result of taking the drugs themselves. To unr

A related study on resilience and genes posted on on this weblog May 7th (see also the Dec. 2nd post on antisocial behavior) turns this relationship on its head. It too notes that a genetic predisposition to certain behavior--in this earlier report, the ability to tough it out in the face of adverse circumstances--is triggered or not by environmental influences. In recent years, biological science has proposed a new paradigm. The latest research shows that resilience can best be understood as an interplay between particular genes and environment — GxE, in the lingo of the field. Researchers are discovering that a particular variation of a gene can help promote resilience in the people who have it, acting as a buffer against the ruinous effects of adversity. In the absence of an adverse environment, however, the gene doesn't express itself in this way. It drops out of the psychological picture. "We now have well-replicated findings showing that genes play a major role in influe