Overview of Substance Use Disorders

Substance use disorders are a major source of morbidity and mortality, contributing to a significant proportion of deaths in the United States and worldwide each year. A substantial rise in deaths related to drug overdoses in recent decades has drawn increasing public attention to this issue. However, the majority of individuals struggling with substance use disorders remain untreated. The financial costs and health burden are substantial. This review provides a broad overview of substance-related and addictive disorders. The evolution of the classification system is described, and the diagnostic criteria for the various substance use disorders are reviewed. Epidemiology and etiologic considerations, including neurobiological pathways, genetics, environmental influences, and dimensional risk factors, are examined. Finally, individual substances and their related disorders are reviewed, including alcohol, caffeine, cannabis, hallucinogens, inhalants, opioids, sedative/hypnotics, stimulants, tobacco, and other or unknown substances. Intoxication and withdrawal syndromes are described where applicable, and clinical management concepts are discussed.  This review contains 6 figures, 5 tables, and 71 references. Key words: abuse, addiction, alcohol, caffeine, cannabis, dependence, diagnosis, DSM-5, epidemiology, hallucinogen, hypnotic, inhalant, intoxication, methamphetamine, nicotine, opioid, sedative, stimulant, substance use disorders, tobacco, tolerance, withdrawal