Alcoholism is common, serious, and expensive. Physicians encounter alcohol-related cirrhosis, cardiomyopathy, pancreatitis, and gastrointestinal bleeding, as well as intoxication and alcohol addiction, on a daily basis. Alcoholism is also associated with many cancers. Wernicke encephalopathy and Korsakoff psychosis are also important causes of chronic disability as well as dementia. Fetal alcohol syndrome is a leading cause of mental retardation. In addition, accidents (especially automobile), depression, dementia, suicide, and homicide are important consequences of alcoholism.
Alcohol-related diseases are discussed in separate articles. The focus of this article is screening, diagnosis, treatment, and new research findings on the natural history and heritability of alcoholism.
Alcohol affects virtually every organ system in the body and, in high doses, can cause coma and death. It affects several neurotransmitter systems in the brain, including opiates, GABA, glutamate, serotonin, and dopamine. Increased opiate levels help explain the euphoric effect of alcohol, while its effects on GABA cause anxiolytic and sedative effects.
Alcohol inhibits the receptor for glutamate. Long-term ingestion results in the synthesis of more glutamate receptors. When alcohol is withdrawn, the central nervous system experiences increased excitability. Persons who abuse alcohol over the long term are more prone to alcohol withdrawal syndrome than persons who have been drinking for only short periods. Brain excitability caused by long-term alcohol ingestion can lead to cell death and cerebellar degeneration, Wernicke-Korsakoff syndrome, tremors, alcoholic hallucinosis, delirium tremens, and withdrawal seizures. Opiate receptors are increased in the brains of recently abstinent alcoholic patients, and the number of receptors correlates with cravings for alcohol.
These statistics are based on the US National Longitudinal Alcohol Epidemiologic Study. Alcoholism is prevalent in 20% of adult hospital inpatients. One in 6 patients in community-based primary care practices had problem drinking. The following apply to the US adult population:
- Current drinkers - 44%
- Former drinkers - 22%
- Lifetime abstainers - 34%
- Abuse and dependency in the past year - 7.5-9.5%
- Lifetime prevalence - 13.5-23.5%
Alcoholism is slightly more common in lower income and less educated groups. Vaillant studied the natural history of alcoholism and the differences between college-educated and inner-city alcoholic persons. He followed 2 cohorts (over 400 patients) of alcoholic patients over many years.1
According to Vaillant's research, inner-city men began problem drinking approximately 10 years earlier than college graduates (age 25-30 y vs age 40-45 y). Inner-city men were more likely to be abstinent from alcohol consumption than college graduates (30% vs 10%) but more likely to die from drinking (30% vs 15%). A large percentage of college graduates alternated between controlled drinking and alcohol abuse for many years. Returning to controlled drinking from alcohol abuse is uncommon, no more than 10%; however, this figure is likely to be high because it was obtained from self-reported data. Mortality in both groups was related strongly to smoking. Abstinence for less than 5-6 years did not predict continued abstinence (41% of men abstinent for 2 y relapsed).
The World Health Organization examined mental disorders in primary care offices and found that alcohol dependence or harmful use was present in 6% of patients. In Britain, 1 in 3 patients in community-based primary care practices had at-risk drinking behavior. Alcoholism is more common in France than it is in Italy, despite virtually identical per capita alcohol consumption.
Alcohol use is the third leading cause of preventable death in the United States (after smoking and obesity). Annually, 85,000 deaths are attributable to alcohol at a cost of $185 billion.2, 3 Almost half of these deaths are attributable to alcohol-related injury.
Four percent of the global burden of disease is attributable to alcohol. This figure rises to 7% in North America, Europe, Japan, and Australia and to 12% in Eastern Europe and Central Asia. Worldwide, alcohol is responsible for a percentage of a number of conditions, as follows:
- Cirrhosis - 32%
- Motor vehicle accidents - 20%
- Mouth and oropharyngeal cancers - 19%
- Esophageal cancer - 29%
- Liver cancer - 25%
- Breast cancer - 7%
- Homicides - 24%
- Suicides - 11%
- Hemorrhagic stroke - 10%
Below are the statistically significant relative risks from a study by the American Cancer Society for men and women who consume 4 or more drinks daily. A drink is defined as one 12-oz beer, one 4- to 5-oz glass of wine, or one mixed drink containing 1.5 oz of spirits (80 proof). The relative risk for the noted maladies with consumption of 4 or more drinks daily is as follows:
- Cirrhosis - For men, 7.5; for women, 4.8
- Injuries - For men, 1.3
- Ear, nose, and throat cancer; esophagus cancer; liver cancer - For men, 2.8; for women, 3
Moderate alcohol consumption (1-2 drinks/d) reduces the risk of cardiovascular disease in men and women by approximately 30%.4, 5, 6 The effect of heavy alcohol consumption on the risk of cardiovascular disease varies in different studies. The person's drinking pattern appears to have an effect on cardiovascular disease. Drinking with meals may reduce the risk, while binge drinking increases risk (even in otherwise moderate drinkers).
Moderate alcohol consumption appears to increase the risk of breast cancer in women. Total mortality is reduced with moderate alcohol consumption but not with heavy alcohol consumption; the cardiovascular benefit is offset by cirrhosis, cancer, and injuries. The amount of alcohol associated with the lowest mortality appears to be 2 drinks per day in men and 1 drink or fewer per day in women. Moderate alcohol consumption reduces the risk of developing diabetes, but heavy alcohol consumption may increase the risk. The cardiovascular benefit becomes important in men older than 40 years and in women older than 50 years. The risk of hypertension is increased with 3 or more drinks daily.
No benefits are noted in people at low risk for coronary disease (men <40>7 This effect was exacerbated by binge drinking.
Of men aged 18-25 years, 60% binge drink. (Binge drinking is defined as 5 alcoholic drinks for men [4 for women] in a row.) Binge drinking significantly increases the risk of injury and contracting sexually transmitted diseases. Women who binge drink at this age are at higher risk of becoming pregnant and potentially harming an unborn child. (Any amount of alcohol consumption during pregnancy is risky.)
More than three quarters of all foster children in the United States are children of alcohol- or drug-dependent parents. From 60-70% of reported domestic violence incidents involve alcohol. Half of all violent crime is alcohol or drug related.
Overall, morbidity and mortality are related strongly to smoking, and people who drink heavily are less likely to quit smoking. Additionally, persons who begin smoking early are more likely to develop problems with alcohol.
With regard to pregnancy, fetal alcohol syndrome is the leading known cause of mental retardation (1 in 1000 births). More than 2000 infants annually are born with this condition in the United States. Alcohol-related birth defects and neurodevelopmental problems are estimated to be 3 times higher. Even small amounts of alcohol consumption may be risky in pregnancy. A 2001 study by Sood et al reported that children aged 6-7 years whose mothers consumed alcohol even in small amounts had more behavioral problems.8 In a study from 2003, Baer et al showed that moderate alcohol consumption while pregnant resulted in a higher incidence of offspring problem drinking at age 21 years, even after controlling for family history and other environmental factors.9 All women who are pregnant or planning to become pregnant should avoid alcohol.
The 2 largest studies, the US National Comorbidity Survey and the Epidemiologic Catchment Area Survey, both showed a lower prevalence of alcoholism in African Americans than in white Americans. The prevalence was equal or higher in Hispanic Americans compared with white Americans.
Studies of Native Americans and Asian Americans are smaller. These studies indicate the prevalence of alcoholism is higher in Native Americans and lower in Asian Americans when compared with white Americans.
Alcoholism is at least twice as prevalent in men as it is in women. In the National Comorbidity Survey, it was 2.5 times more prevalent in men than in women. The lifetime prevalence was 20% in men and 8% in women. For alcohol abuse or dependence in the past year, the rates were 10% for men and 4% for women.
Women do not metabolize alcohol as efficiently as men. Hazardous drinking (not alcoholism) is greater than 1 drink daily for women and greater than 2 drinks daily for men.
Problem drinking in women is much less common than it is in men, and the typical onset of problem drinking in females occurs later than in males. However, progression is more rapid, and females usually enter treatment earlier than males. Women more commonly combine alcohol with prescription drugs of abuse than do males. Women living with substance-abusing men are at high risk.
Alcohol problems are less likely to be recognized in women, and women with alcohol problems are less likely to be treated. This may be because women are less likely than men to have job, financial, or legal troubles as a result of drinking.
The prevalence of alcoholism declines with increasing age. The prevalence in elderly populations is unclear but is probably approximately 3%. A study of the US Medicare population found that alcohol-related hospitalizations were as common as hospitalizations for myocardial infarction.
Among older patients with alcoholism, from one third to one half develop alcoholism after age 60 years. This group is harder to recognize. A recent population-based study found that problem drinking (>3 drinks/d) was observed in 9% of older men and in 2% of older women. Alcohol levels are higher in elderly patients for a given amount of alcohol consumed than in younger patients.
Author: Warren Thompson, MD, FACP, Associate Professor, Department of Internal Medicine, Mayo Medical School