Wednesday, April 28, 2010

Genes for alcoholism found

Those pesky genes again!

Scientists have identified new genes and pathways that influence an individual's typical pattern of brain electrical activity, a trait that may serve as a useful surrogate marker for more genetically complex traits and diseases. One of the genes, for example, was found to be associated with alcoholism.

A report of the findings by researchers at the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the National Institutes of Health, appears online this week in the Proceedings of the National Academy of Sciences.

"This important advance sustains our hope for the potential of genome-wide association techniques to further the study of complex genetic disorders such as alcoholism," notes NIAAA Acting Director Kenneth R. Warren, Ph.D. Genome-wide association studies (GWAS) allow researchers to rapidly scan the complete set of DNA of many individuals to find genetic variations associated with a particular disease or condition.

"One of the challenges in identifying the genes that underlie alcoholism is the large degree of genetic and environmental variability associated with the disease," explains first author Colin A. Hodgkinson, Ph.D., a geneticist in the NIAAA Laboratory of Neurogenetics. "Such variability has impeded even GWAS efforts to identify alcoholism genes. To overcome those difficulties, we used GWAS techniques to search for genetic variants related to EEG, or brain wave, patterns in a comparatively small sample of several hundred Native American individuals."

As unique as an individual's fingerprints, EEG (electroencephalogram) patterns are highly heritable, and have been associated with alcoholism and other psychiatric disorders. The high degree of genetic similarity and common environmental exposure shared by the Native American individuals that comprised the study sample aided this search.

Working with David Goldman, M.D., chief of the NIAAA Laboratory of Neurogenetics, Dr. Hodgkinson and colleagues identified multiple genes that were associated with the amplitude, or height, of two of the four characteristic electrical frequencies that make up the wave patterns found in EEG recordings.

One of the genes, for example, was found to account for nearly 9 percent of the EEG theta wave variability seen in the Native American sample. Theta waves are relatively low-frequency brain waves, and previous studies have shown that their amplitude is altered among alcoholics. The researchers then showed that the same gene accounted for about 4 percent of theta wave variability in a sample of North American whites. The gene's diminished effect among whites, they noted, was likely a reflection of the greater genetic variability present in that sample. In the same study Dr. Goldman's group went on to show that genetic variation in one of the genes identified for theta wave variability was also associated with an altered risk for alcoholism.

"While our main findings are for genes that influence EEG wave patterns, this study represents an important step toward the use of EEG as a surrogate marker for alcoholism," notes Dr. Goldman. "It also reveals new molecular pathways involved in addiction processes."


Fresh fears for games addicts

You can overdo anything. Even drinking too much water can kill you. In general, however, games are pro-social, just as harmless as drinking normal amounts of water. Those who do use games excessively may be using them as non-drug therapy for problems -- which could be desirable. Better than heroin, anyway

PLAYING computer games is as popular as watching TV, but some gamers have developed an addiction that can be as costly and debilitating as drug and alcohol dependence.

A study by the Australian and New Zealand College of Psychiatrists, conducted online among 1945 participants, showed 8 per cent were identified as problem gamers. These players admitted to gaming for extended periods - in some cases more than eight hours a day - had fewer friends in real life and had even lost a significant relationship as a result of excessive play.

Other problems extended to craving more play time, and restlessness or irritability if they couldn't get back to the controller. Some also said their gaming activities interfered with school or work performance while others identified physical issues including sleep reduction, back pain and sore eyes.

The survey also revealed a financial fallout with some problem players spending excessive amounts of money to have the latest games, hardware and virtual currency to pay for their addiction.

Psychiatrist Guy Porter, who co-wrote a paper based on the survey's findings for the Australian and New Zealand Journal of Psychiatry, said the syndrome of video game dependence was similar to drug and alcohol addiction. "Any pleasurable activity has the potential to become addictive or to form a repetitive pattern of use," he said.

"Games are very enjoyable and provide a very positive experience for most people who use them. "But there are a small number of people out there - those who are playing for eight hours plus a day - who have got a problem with it."

There have been cases in Asia where people have died after marathon sessions, lasting days, playing games such as World of Warcraft and Starcraft.

Dr Porter said that aside from the duration of play, other issues needed to be examined. "The issue is whether it is the actual game they are playing or an underlying mental-health problem that the person has," he said.

"Someone could have anxiety or depression, social problems, marriage problems, out of a job, financial problems and the only stress relief they have is playing a game. "A lot of games, in particular online games, can offer a sense of achievement in the virtual world which outweighs the sense of achievement in real life. "A lot of people find it more rewarding to achieve online objectives in a game rather than real-world objectives."


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