Drugs that produce substance use disorders all activate the brain reward system, but each class of drugs activates the system by a different pharmacological mechanism. Thus, this chapter is organized according to pharmacological class. The emphasis is on pharmacotherapy, but all treatment using medications should be accompanied by counseling or psychotherapy according to the patient's needs. Medication combines very well with psychotherapy, including self-help groups such as Alcoholics Anonymous (AA). The majority of patients also have an additional mental disorder (besides the addictive disorder) such as depression, anxiety, or bipolar disorder. These comorbidities require specific treatment including medication and psychotherapy. The best treatments for addiction complicated by additional psychiatric disorders are delivered in an integrated fashion, preferably from the same therapist. All psychiatrists should be able to manage substance use disorders, especially those that co-occur with other psychiatric diagnoses.