This article examines several circumstances in which psychotic symptoms coexist with substance abuse. It reviews psychotic states that may occur as a result of alcohol and other drug use, including intoxication, overdose and withdrawal, offering medication guidelines for managing these situations. It also examines psychiatric disturbances in which psychotic symptoms are recurrent features, exploring patients' self-medication practices and some strategies to address them, as well as difficulties commonly encountered with prescription medications. It briefly discusses other psychosocial interventions that play a significant role in the treatment of the dual diagnosis patient.