If you were trying to find something to blame alcoholism on, genetics would be a good place to start: As much as 50-60% of the risk of becoming an alcoholic is determined by a person’s genes (1). We’ve discussed the genetics of addiction in general as they relate to other condition like ADHD, depression, and anxiety, but the risk that a person may become an alcoholic also depends on their sensitivity to alcohol’s effects, development of tolerance, susceptibility to withdrawal symptoms and alcohol-related organ damage, among others.
Alcohol related genes and alcoholism
The genetic causes of alcoholism are not always simple and straight-forward, especially because genes interact with one another (and the environment) in ways that can create unexpected results. However, some aspects of the genetics of alcoholism are clear, like the case of the genes that affect the speed with which liver enzymes will break down (metabolize) alcohol and its byproducts. Some people have a gene variation which produces liver enzymes that have trouble breaking down acetaldehyde (ALDH2-2, very common among Asians), a basic breakdown product of alcohol. As the levels of acetaldehyde increase, people experience flushing, nausea and rapid heartbeat which makes them less likely to consume alcohol and therefore less likely to become alcoholics. Not surprisingly, alcoholism rates have been historically low in Asian populations. However, recent increasing trends of alcoholism in Japan show that if you work at it hard enough, even a genetic predisposition that is supposed to protect you from alcoholism is no match for good old social pressures to drink.
Researchers have identified one neuropeptide (called NPY) that is located near known alcohol-related traits and indicates an alcohol preference in rats, consequently increasing response to alcohol (1). The effects of alcohol are increased with certain forms of NPY and that gene has been linked to addiction-related, and anxiety, behaviors (2). It is also generally accepted that genes that affect the activity of serotonin and GABA (one of alcohol’s main targets in the brain and body) are likely to be involved in alcoholism risk.
It is important for everyone to remember that there is a predisposition to becoming an alcoholic and that alcoholism is a disease, not simply an outcome of poor behavior . There are ways to treat both the physical symptoms and the underlying addiction in alcoholics.
We’ve barely scraped the surface of the numerous influences on alcohol’s effects, and the predisposition to alcoholism, but hopefully this post leaves you with a slightly better appreciation of the complexity of the matter…
Co-authored by: Jamie Felzer
1. Alcohol Alert-National Institute on Alcohol Abuse and Alcoholism. No.60. July 2003
2. Anxiety and alcohol abuse disorders: a common role for CREB and its target, the neuropeptide Y gene. Trends in Pharmacological Sciences, Volume 24, Issue 9, September 2003, Pages 456-460.