Gene linked to stress-related drinking

 作者:丰撇耖     |      日期:2019-03-05 05:17:03
By Emma Young Variations in a key gene might explain why some people turn to alcohol when they are stressed, a German study suggests. Mice lacking the gene started to drink three times more alcohol than normal mice after they suffered a stressful experience. Six months later, they still drank significantly more. The gene is for CRH1, a type of receptor in the corticotropin-releasing hormone system in the brain. This system mediates hormonal and behavioural responses to stress. The CRH1 receptor has previously been linked to stress-related psychiatric disorders. “Patients with alterations in this gene may be particularly susceptible to stress, and may respond with drinking,” says Rainier Spanagel of the University of Heidelberg, who led the work. David Ball, an expert on genetic links to alcoholism at the Institute of Psychiatry, UK, says the study “neatly brings together genetic predisposing factors with stress in the possible development of excessive alcohol consumption”. He thinks the finding could be used to help tailor more effective treatments to individual alcoholics. Stress is the biggest cause of relapse for many recovering alcoholics, says Alan Leshner, head of the American Association for the Advancement of Science, and a former director of the US National Institute on Drug Abuse. “This important study points both to the underlying mechanisms of this effect and potential targets for prevention and treatment efforts,” he says. Other work has also shown that stressful life events can be triggers for alcoholism. Psychologists might be able to help patients with alterations in the gene by teaching them coping strategies to deal with stress, says Spanagel. His team first gave normal and mutant mice a choice between water and ethanol solutions at different concentrations. Both chose a solution of eight per cent ethanol. The mice were then exposed to two types of stress. The first involved an attack by an unfamiliar mouse and the other required the mice to swim. Each stressful experience took place on three consecutive days. After each stressful experience, both sets of mice continued to drink the normal amount of alcohol. But three weeks later, the mutant mice suddenly began drinking much more alcohol. Six months on, they were still drinking significantly more. Spanagel says he cannot explain why three weeks passed before the mutant mice started to increase their alcohol intake. But he says that previous studies have found a wide range of behavioural responses to stress, some immediate and some delayed. More research is needed to find out whether mutations in the CRH1 gene might contribute to alcoholism in people. But Spanagel says he is confident that mice responses to alcohol are a good model for human behaviour. Journal reference: Science (vol 296,