What is the US Epidemiology Catchment Area (ECA) study?
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 personality disorder.
There has been little research completed in regards to relapse in drug-related disorders. As with people with an alcohol-related disorder, people with a drug-related disorder also make little use of professional assistance to help their problems.
How about subsequent community surveys in developed countries?
After the ECA, there have been many more studies on alcohol and drug use. Prevalence comparisons are difficult to make because different methodologies and versions of the DSM have been used in the various studies. Yet comparable trends have been found.
America
Research supports the previously discussed results from the ECA study. Some important findings:
Alcohol and drug dependence is often experienced with other psychiatric disorders.
Most people with alcohol or drug-related problems do not seek professional help, although those with drug problems tend to seek help more often than those with alcohol problems. People with comorbid disorders looked for help more often.
Nicotine dependence was associated with many other psychiatric disorders.
England and Europe
Similar results were also found here.
New Zealand
Similar results were found. After correction, the disorders related to substance use in the Maori were twice as high compared to the rest of the population.
Australia
Some additional research results:
Disorders related to substance abuse were more common among people who live alone compared to people in a relationship.
The prevalence of disorders related to substance abuse was higher among the unemployed.
People born in English-speaking countries had drug-related disorders more often than people from non-English-speaking countries.
The level of education or the living environment (countryside/city) did not influence the prevalence of disorders related to substance abuse.
Tobacco dependence was related to affective or anxiety disorders.
