Genes, serotonin and alcohol

Researchers at the University of Virginia have been investigating the links between a variation of the gene SLC6A4, which is linked to the neurotransmitter serotonin, and how heavily people with alcohol problems drink. The study, of 275 people seeking treatment for drink problems, found that one variation of the gene had a significant association with drinking intensity. Heavy drinking increases serotonin in the brain for a time but over the years chronic drinking reduces serotonin levels leading to a vicious circle in which people drink more to make up the deficit.

http://www.sciencedaily.com/releases/2009/02/090204121517.htm