People who drink, smoke and take drugs could be more at the mercy of their genes than was previously realised, research showed . A study involving more than 20000 people has suggested that particular genes can influence personality traits linked to unhealthy behaviour.
Cancer Research UK scientists at Oxford University pooled data from 46 separate studies looking at the link between human behaviour and inheritance. The research focused on genes that control chemicals used to transmit signals between brain cells. Researchers found that one version of the human serotonin transporter gene (5HTT-LPR) was strongly associated with anxious personalities. Individuals with this gene variant were the sort who find social interaction stressful and may take refuge in substance abuse. The scientists found a weaker link between a variant in a second gene, the dopamine D4 receptor, and extrovert personality traits. Such people are more likely to smoke or take drugs because of a tendency to gamble with their health and seek out novelty.
The chief researcher, Dr Marcus Munafo, said: “Our study suggests that there is a genetic basis to certain kinds of personality trait, which may be important in influencing whether people take up habits like smoking or whether they can subsequently give them up. Understanding genetic influences on personality is important if we are to design health campaigns that are effective for the widest possible range of people. “We also know, through drugs such as antidepressants, that is possible to influence these behaviours, and our research may open the way to new types of medication to help people overcome cancer-causing addictions.”
Scientists do not know precisely why particular genetic variants may influence personality, but have some clues. The 5HTT-LPR variant appears to reduce levels of the serotonin transporter molecule, in turn influencing levels of serotonin activity. Serotonin helps to control emotions such as anxiety and depression. Variations in the dopamine D4 receptor seem to alter the brains response to dopamine, which is thought to be associated with novelty seeking behaviour and pleasure, and may have a role in substance abuse.
Source: Journal of Molecular Psychiatry June 2003
