The ECA study was the first major epidemiological study (1991) on alcohol and drug problems in different communities. twenty thousand people in various American states were interviewed personally. A standardized interview which identified whether a mental disorder was present or absent was implemented to forty psychiatric diagnoses which contained substance dependency. A distinction was made between alcohol abuse and alcohol dependence. Disorders related to alcohol abuse were the second most common disorders. One in seven people reported alcohol problems at least once in life. Men reported this five times more often than women and the disorders were more common at a younger age. Heavy drinking led to problems rather than light drinking. People with alcohol-related problems also had to deal with another related diagnosis, such as drug abuse or schizophrenia, in almost half of the cases.Alcohol dependency experienced an 'early onset' among eighty percent of the participants: the first symptoms were visible from their thirtieth year of life. There is a high remission rate, fifty percent of those who experienced this disorder did not experience any symptoms for at least a year. Most individuals who recovered from their alcohol dependence did so on their own and without professional guidance.In addition to alcohol-related disorders, drug abuse and drug dependence were also looked at. Approximately one third of the participants had used at least one type of drug during the course of life. Cannabis was the most common form of drugs. Drug abuse or dependence can be determined in six percent of the population. Here, too, men had drug-related problems more often than women, and the problems were more common at a younger age. More than two thirds of people with a drug-related disorder also received a second diagnosis which was usually either alcohol-related disorders or an antisocial...