Prevalence
Besides caffeine, alcohol is the most widely used psychoactive drug in the world; of the 160 million Americans of legal drinking age, about 112 million drink, says Robert Julien in his book, A Primer of Drug Action. About seven million are alcoholics, he says.
He also states that 30-50% of alcoholics show signs of major depression.
The minimal influence of genetics
In the co-morbid relationship between alcohol addiction and depression, it seems that depression is the primary disorder.
Many, if not all alcoholics do not have primary alcoholism, but a psychopathology such as depression that triggers them to drink, states Ulf Berggren et al. in a study published by the journal Alcohol and Alcoholism.
The study recognized that there is a genetic component to alcohol addiction; human dopamine receptor genes have a detectable variation called the DRD2 TaqI polymorphism allele.
Their findings suggest that those who possess the allele variation have only a small tendency towards addiction to opiates and endorphin releasing drugs like alcohol.
They also note that although this allele is slightly more common in alcoholics and opiate addicts, it is not by itself an adequate predictor of alcoholism.
Self-medicating for depression
A prevalent theory of alcohol addiction is people drink to self-medicate for depression. Drinking causes a decrease in panic and anxiety, impairs cognitive functioning, and can cause “alcohol myopia,” where the immediate aspects of a situation have disproportionate emotional and behavioral influences, Roberts says- and relief from panic and anxiety becomes positive reinforcement for those who suffer from psychological conditions such as depression.
In fact, many depressed or anxious alcoholics self-reported drinking to relieve symptoms of sadness or nervousness according to Mark Shuckit in his article Alcohol, Anxiety, and Depressive Disorders, published by the National Institute on Alcohol Abuse and Alcoholism.
As it pertains to the link to depression, alcohol’s affect on the serotonin system is worthy of a closer look. Serotonin regulates mood and chronic alcohol intake augments serotonin activity, so serotonin dysfunction might in some cases be a motive for alcoholism, Roberts says. In effect, alcohol does what antidepressants aim to do, increase the availability of serotonin- relieve depression.
Implications
Alcoholism is a multifaceted disease closely related to depression. Although some people drink to manage their mood, alcohol itself is a known depressant. Obviously drinking is not an advisable way to treat depression. Nonetheless, treating depression along with neurochemical addiction is necessary for effective and full recovery from alcoholism.
Sources:
Berggren, Ulf, and Claudia Fahlke, Erik Aronsson, Aikaterini Karanti, Matts Eriksson, Kaj Blennow, Dag Thelle, Henrik Zetterberg, and Jan Balldin (2006). The TAQI DRD2 A1 Allele is Associated with Alcohol-Dependence Although its Effect Size is Small. Alcohol and Alcoholism 41(5):479-485.
Julien, Robert M. (2005). A Primer of Drug Action. 10th Ed. New York New York: Worth Publishers.
Schuckit, Marc A. (1996). Alcohol, Anxiety, and Depressive Disorders. National Insitute on Alcohol Abuse and Alcoholism, 81-85.
