Persons addicted to drugs, but who are no longer using drugs illegally and are receiving treatment for drug addiction or who have been rehabilitated successfully, are protected by the ADA from discrimination on the basis of past drug addiction.
For example: An addict who is currently in a drug rehabilitation program and has not used drugs illegally for some time is not excluded from the protection of the ADA. This person will be protected by the ADA because s/he has a history of addiction, or if s/he is "regarded as" being addicted. Similarly, an addict who is rehabilitated or who has successfully completed a supervised rehabilitation program and is no longer illegally using drugs is not excluded from the ADA.
However, a person who casually used drugs illegally in the past, but did not become addicted is not an individual with a disability based on the past drug use. In order for a person to be "substantially limited" because of drug use, s/he must be addicted to the drug.
To ensure that drug use is not recurring, an employer may request evidence that an individual is participating in a drug rehabilitation program or may request the results of a drug test (see below).
A "rehabilitation program" may include in-patient, out- patient, or employee assistance programs, or recognized self-help programs such as Narcotics Anonymous.