Researchers looking at a genetic variation that is known to increase susceptibility to anxiety and depression have found that it affects females more than males. The discovery, published in the Proceedings of the National Academy of Sciences, was made following the study of monkeys, but the results may also be applicable to humans. Women with the genetic variation and who have suffered abuse as children may be particularly susceptible.
The gene variation is in a promoter, the area of DNA that controls how much of the time a gene is 'switched on'. The promoter is for a gene that makes a protein involved in regulating the brain chemical serotonin (5HT - 5 hydroxy-tryptamine). Scientists have long known that levels of serotonin are linked to feelings of emotional well-being - a study published last year showed that a gene involved in serotonin production appears to affect a person's ability to cope with stressful life events.
The researchers, working at the US National Institute of Alcohol Abuse, measured the levels of stress hormones in 190 rhesus monkeys. Females with the 's allele' genetic variation and a history of adversity had the highest levels of the stress hormones. The researchers do not know why this variation affects females more than males, but it is possible that it is due to sex hormones.
Researcher Iain Ryrie warned that 'overstressing genetic risks misses this point and the opportunities it presents'. He explained that 'there is much we can do after our genes are laid down to enhance our ability to cope with stress and thus avoid some of its debilitating consequences'.