Years of observational medical data on Alcoholism and its causes in various populations has revealed that a number of complex social, environmental, and even genetic factors may influence the risk of developing Alcohol Use Disorder (AUD).
A family history of alcoholism shows a clear genetic susceptibility to this disorder because of a mutation in the genes responsible for the metabolism of alcohol. Interestingly, a publication has demonstrated how alcohol consumption at an early age could influence gene expression, thus increasing the risk of alcohol abuse or dependence. So, individuals having a genetic predisposition to alcoholism are twice as likely to becoming chronic alcoholics at a younger age. The risk of developing alcoholism is higher if they begin drinking at a younger age; so 40% of alcoholics have already been addicted to excessive alcohol consumption by the time they reach adolescence. This controversial causal-association between young age and genetic susceptibility to alcoholism is not yet widely accepted by researchers or data scientists and is still under debate.
Human Genetic Variation in Population
On the other hand, genetic variations between different racial groups like African, East Asian and Indo-racial groups also control the risk of developing Alcohol Use Disorder (AUD). For instance, the genes influencing the rate of alcohol metabolism in one’s system majorly impacts individuals’ liking of alcoholic beverages. Many in the Asian population are known to carry a genetic variant of the alcohol dehydrogenase allele (ADH1 B*- functions for rapid metabolism of alcohol), which deferentially affects alcohol metabolism giving symptoms of nausea and increased heart-rate. Such genetic dispositions help in avoiding alcohol consumption due to its unpleasant effects and in turn help prevent developing alcoholic habits. African-American and Native American sub-populations have the normal allele ADH1 B* giving them the ability for faster alcohol metabolism and a reduced risk of developing Alcohol abuse or dependence disorder. Therefore, such genetic variations among different population subsets also play a major role in developing AUD.
As much as genetics may play a role in developing alcoholism, environmental factors and gene-environment interactions are also vital for understanding the causes of alcoholism. For instance, any severe childhood traumatic incident could increase the risk of alcohol dependency at a younger age owing to situational factors. Similarly, the lack of family support during childhood and adolescence could lead to an increased risk of developing alcoholic habits or other forms of addictions. Therefore, familial factors and genetics together with the growth environment show an increased sensitivity to alcohol abuse or dependency. Also, the neurotoxic effects of alcohol vary from person-to-person, causing higher cortical degeneration in those who are genetically susceptible to developing Alcohol Use Disorder. Such toxic effects on the cerebral cortex further increase the risk of impulsive behavior, which contributes to the development, sustenance, and prolonging of Alcohol dependence and Abuse. Medical evidence based on case studies have clearly shown that some of alcohol-induced neurotoxic effects on the Central Nervous System (CNS) are reversed following a period of abstinence.
Epigenetics and Alcoholism
Epigenetics is a field of genetics which studies variations in gene expression caused by external and environmental factors. Heavy alcohol addiction has also been linked to epigenetic changes which in turn exponentially increases the risk of developing Alcoholic abuse and dependence. More research studies are required to thoroughly understand how epigenetics also plays a role in causing alcoholism.