"Traumatic" addiction follows a trauma, generally with an abrupt and acute onset. "Actual" addiction involves an active conflict in a youth's social environment that produces feelings of uneasiness and other disturbing factors. "Transitional" addiction is characterized by various psychological disorders that accompany the onset of drug addiction, and "sociopathic" addiction involves a psychosocial conflict expressed in "acting out" behavior and a number of personality disorders. Each type of addiction differs in onset, evolution, prognosis, and other characteristics relevant to the treatment of drug-addicted persons. Thus, the classification helps in making an appropriate selection of a treatment method and in the evaluation of a treatment program. Traumatic and actual types of addiction have a more favorable prognosis; individual psychotherapy and support in a medical setting is effective for the traumatic type of addiction; treatment in a family setting appears to be suitable for actual and transitional types of addiction; and the therapeutic community may prove to be effective in the treatment of persons affected by sociopathic addiction. 18 references. (Author abstract modified)