Repeated use of a psychoactive substance or substances to the extent that the user (referred to as an addict) is periodically or chronically intoxicated, shows a compulsion to take the preferred substance (or substances), and has great difficulty in voluntarily ceasing or modifying substance use, and exhibits determination to obtain psychoactive substances by using almost any means.
Good outcomes of the treatment depend on treatment length, patient participation and family support. By viewing addiction as a chronic disease and offering continuing care and monitoring, programs can succeed, but this will often require multiple episodes of treatment and readily readmitting patients that have relapsed.
Family and friends can motivate an addict to enter and stay in treatment, especially for adolescents. Involvement of a family member in an individual's treatment program can strengthen and extend treatment benefits.