Currently, the treatment and rehabilitation of drug addicts in Thailand is conducted in three systems. The voluntary system permits the drug addicts to apply voluntarily for treatment; such voluntary participation in treatment statutorily protects the addict from criminal justice processing. Under the convicted system, treatment and rehabilitation are provided for addicts who have been convicted of narcotics offenses and have been sentenced by the court to imprisonment or probation. The compulsory system provides compulsory treatment in accordance with law; those who are alleged offenders and suspected of being drug addicts are sent for drug-use assessment. Diagnosis of drug use mandates treatment in a center. The treatment procedure involves the preadmission stage, the detoxification stage, the rehabilitation stage, and the aftercare stage. Guidelines to prevent and solve drug addiction among youth focus on the family, the school, the welfare service, and use of mass media.