Blood and urine tests can detect recent use of alcohol and other chemical substances but there is no precise test to diagnose addiction. Instead, doctors look for specific patterns of behavior.
The guidelines for a diagnosis of addiction, technically called "psychoactive substance dependence" require at least three of these statements to be true: The substance is taken in larger amounts or over a longer period than the person intended. There is persistent desire for the drug or unsuccessful efforts to stop its use.
The person spends a great deal of time trying to get the substance, taking it or recovering from its effects. Use of the substance disrupts social obligations or work activities. The person continued to use the substance despite knowing that it is causing problems; an example would be excessive drinking, even though it makes an ulcer worse or threatens loss of job.
There is marked tolerance, meaning that increasing amounts are needed to achieve the same results. For example, it now takes an entire bottle of liquor to become intoxicated compared to three or four drinks in the past. Attempts to stop using the substance produce withdrawal symptoms. The substance is taken to avoid the withdrawal symptoms.
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