Longman Dictionary of Contemporary English
Wikipedia
Drug rehabilitation (often drug rehab or just rehab) is a term for the processes of medical or psychotherapeutic treatment, for dependency on psychoactive substances such as alcohol, prescription drugs, and street drugs such as cocaine, heroin or amphetamines. The general intent is to enable the patient to cease substance abuse, in order to avoid the psychological, legal, financial, social, and physical consequences that can be caused, especially by extreme abuse. Treatment includes medication for depression or other disorders, counseling by experts and sharing of experience with other addicts. Some rehab centers include meditation and spiritual wisdom in the treatment process. A few centers also treat gambling with the same techniques as are used in drug rehabilitation.