Alcoholism, or alcohol addiction, is a disease characterized by a loss of control over drinking, preoccupation with drinking, compulsion to drink, inability to stop, and the development of tolerance and dependence. Alcoholics rely on drinking to enhance social situations, relieve stress, anxiety and guilt. Periods of abstinence involve intense cravings and potentially dangerous withdrawal symptoms. Denial of the role that alcohol plays in damaged relationships, financial problems and the deterioration of health is a symptom of alcohol addiction. Factors involved in the development of alcoholism are probably genetic, environmental and psychological.
Genetic
Strong evidence suggests that the high rate of a first-degree relative's risk of alcoholism results from shared genetic risk factors rather than from purely environmental ones, according to the National Institute on Alcohol Abuse and Alcoholism (NIAAA). One of the major genetic factors is tolerance, which is the decrease in sensitivity to alcohol that develops with exposure to alcohol. Individuals who develop a high tolerance, or low sensitivity, to alcohol are at increased risk for alcohol dependency.
Genes that determine expression of the liver enzyme aldehyde dehydrogenase 2 (ALDH2) have been identified. They take two forms, or alleles, and children receive one from each parent. ALDH2-1 allows for rapid metabolism of alcohol. ALDH2-2 is inactive, creating a buildup of acetaldehyde when alcohol is ingested. An individual who has one of each type will have a normal tolerance for alcohol. Those who have a pair of ALDH2-2 alleles, will experience flushing, nausea and a rapid pulse after ingesting a small amount of alcohol; consequently, their risk of alcoholism is low. A third possible combination is two ALDH2-1 alleles. This individual will have a high tolerance (low sensitivity) to alcohol and an increased risk of developing alcoholism.
The NIAAA also reported on studies that looked at twins who were raised separately and at adopted children, which indicated that alcoholism runs in families. Other genetic factors may play a part in determining personality traits such as impulsiveness, which might raise the risk of alcohol addiction. Researchers agree that genetic factors probably increase vulnerability to a greater degree when combined with environmental exposure to high-risk situations.
Environmental
Parental alcohol dependence increases the risk of childhood abuse or other trauma, which in turn is associated with an increased risk of later alcohol dependence in the children, according to NIAAA. Parental depression plays a similar role and ongoing family conflict is a factor in drinking by children and adolescents. Peers influence behavior as well and genes could play a role in the choice of friends; an inherited impulsiveness might cause that child to seek out equally impulsive friends, for example.
Psychological
NIAAA surveys that focused on psychological disorders have noted that alcohol dependence and depression, anxiety and a history of childhood behavior disorders frequently occur together. As a factor in alcoholism, the cause/effect relationship is difficult to interpret. Depression is a possible risk factor for or it could be a consequence of alcohol dependence. Both disorders could have common risk factors. According to a recent New York Times article on alcoholism, close to half of alcoholics have anxiety disorders, including social phobia and panic attacks, compared to only 15 percent of the general population. However, chronic alcoholism may cause alterations in brain chemistry that produce anxiety and depression.
