Substance-use disorders

Substance use disorder (SUD) is the persistent use of drugs despite substantial harm and adverse consequences to self and others. Related terms include substance use problems and problematic drug or alcohol use. Along with substance-induced disorders (SIDs), they are categorized as substance-related disorders.
Substance use disorders vary with regard to the average age of onset. It is not uncommon for those who have SUD to also have other mental health disorders. The coexistence of both a mental health disorder and a substance use disorder (SUD) is referred to as co-occurring disorders. Substance use disorders are characterized by an array of mental, emotional, physical, and behavioral problems such as chronic guilt; an inability to reduce or stop consuming the substance(s) despite repeated attempts; operating vehicles while intoxicated; and physiological withdrawal symptoms. Drug classes that are commonly involved in SUD include: alcohol (alcoholism); cannabis; opioids; stimulants such as nicotine (including tobacco), cocaine and amphetamines; benzodiazepines; barbiturates; and other substances.
In the DSM-5 (2013), the DSM-IV diagnoses of substance abuse and substance dependence were merged into the category of substance use disorders. The severity of substance use disorders can vary widely; in the DSM-5 diagnosis of a SUD, the severity of an individual's SUD is qualified as mild, moderate, or severe on the basis of how many of the 11 diagnostic criteria are met. The ICD-11 divides substance use disorders into two categories: (1) harmful pattern of substance use; and (2) substance dependence.
In 2017, globally 271 million people (5.5% of adults) were estimated to have used one or more illicit drugs. Of these, 35 million had a substance use disorder. An additional 237 million men and 46 million women have alcohol use disorder as of 2016. In 2017, substance use disorders from illicit substances directly resulted in 585,000 deaths. Direct deaths from drug use, other than alcohol, have increased over 60 percent from 2000 to 2015. Alcohol use resulted in an additional 3 million deaths in 2016.