The most common dual dependence syndrome with alcohol dependence is benzodiazepine dependence, with studies showing 10–20% of alcohol-dependent individuals had problems of dependence and/or misuse problems of benzodiazepine drugs such as diazepam or clonazepam. These drugs are, like alcohol, depressants. Benzodiazepines may be used legally, if they are prescribed by doctors for anxiety problems or other mood disorders, or they may be purchased as illegal drugs. Benzodiazepine use increases cravings for alcohol and the volume of alcohol consumed by problem drinkers. Benzodiazepine dependency requires careful reduction in dosage to avoid benzodiazepine withdrawal syndrome and other health consequences. Dependence on other sedative-hypnotics such as zolpidem and zopiclone as well as opiates and illegal drugs is common in alcoholics. Alcohol itself is a sedative-hypnotic and is cross-tolerant with other sedative-hypnotics such as barbiturates, benzodiazepines and nonbenzodiazepines. Dependence upon and withdrawal from sedative-hypnotics can be medically severe and, as with alcohol withdrawal, there is a risk of psychosis or seizures if not properly managed. Epidemiology The World Health Organization estimates that there are 380 million people with alcoholism worldwide (5.1% of the population over 15 years of age). Substance use disorders are a major public health problem facing many countries. "The most common substance of abuse/dependence in patients presenting for treatment is alcohol." In the United Kingdom, the number of 'dependent drinkers' was calculated as over 2.8 million in 2001. About 12% of American adults have had an alcohol dependence problem at some time in their life. In the United States and Western Europe, 10 to 20% of men and 5 to 10% of women at some point in their lives will meet criteria for alcoholism. Estonia had the highest death rate from alcohol in Europe in 2015 at 8.8 per 100,000 population. In the United States, 30% of people admitted to hospital have a problem related to alcohol. Within the medical and scientific communities, there is a broad consensus regarding alcoholism as a disease state. For example, the American Medical Association considers alcohol a drug and states that "drug addiction is a chronic, relapsing brain disease characterized by compulsive drug seeking and use despite often devastating consequences. It results from a complex interplay of biological vulnerability, environmental exposure, and developmental factors (e.g., stage of brain maturity)." Alcoholism has a higher prevalence among men, though, in recent decades, the proportion of female alcoholics has increased. Current evidence indicates that in both men and