Alcohol abuse and dependence are primarily diagnosed through the use of screening surveys. Several hundred such surveys exist, and they vary in the number and nature of questions they ask. Some of the more common scientifically-validated questionnaires include the Michigan Alcohol Screening Test (MAST), a shorter version called the Brief MAST, the Alcohol Use Disorders Identification Test (AUDIT), and the T-ACE test, designed especially for obstetric patients. These surveys ask a range of questions about frequency of drinking, problems that result, and ability to stop.
There are no definitive laboratory tests that can be used to identify alcoholism. However, certain tests may help detect chronic and/or relapse in alcohol drinking in those who deny it and help evaluate organ damage. According to the Substance Abuse and Mental Health Administration, these include:
- Gamma-glutamyl transferase (GGT), a liver enzyme that is increased by heavy alcohol intake and also by many other conditions that affect the liver
- Mean corpuscular volume (MCV), which measures the size of red blood cells; usually measured as part of a complete blood count (CBC) test; the MCV may increase over time in those who are heavy drinkers but may also be affected by many other conditions.
- Aspartate aminotransferase (AST) and alanine aminotransferase (ALT), enzymes that can indicate liver damage, which is often related to alcohol use
- Carbohydrate-deficient transferrin (CDT), which can indicate relapse to heavy drinking following a period of abstinence but may be less sensitive for women and younger people
- Ethyl glucuronide (EtG) and Ethyl sulfate (EtS), new biomarkers and direct analytes of the breakdown of alcohol
- Phosphatidyl ethanol (PEth), a new but promising biomarker useful for indicating recent drinking
Other laboratory tests used to detect problematic drinking may include:
- Comprehensive metabolic panel (CMP) or liver panel, groups of tests that are used to evaluate organ and liver function
- Magnesium, which can be low in those who are alcoholic due to insufficient dietary intake and loss by the kidneys
A blood alcohol level (ethanol test) can be used to determine if a person has been drinking alcohol recently but does not diagnose alcoholism.