Substance use disorder

Substance use disorder
Other names	Drug use disorder, SUD
A variety of drugs and drug paraphernalia
Specialty	Psychiatry, clinical psychology
Symptoms	Excessive use of drugs despite adverse consequences
Complications	Drug overdose; general negative long-term effects on mental and physical health; acquiring infectious diseases;[1] in some cases criminal behaviour
Risk factors	Having parents or close family members with SUD; other mental health disorders; recreational use of drugs in adolescence and young adulthood[2][3][4][5][6]
Diagnostic method	Symptoms of drug addiction and dependence; inability to lower use; continued use despite awareness of negative consequences, and others
Treatment	Drug rehabilitation therapy

Substance use disorder (SUD) is the persistent use of drugs despite the substantial harm and adverse consequences to one's own self and others, as a result of their use.^[7][8] In perspective, the effects of the wrong use of substances that are capable of causing harm to the user or others, have been extensively described in different studies using a variety of terms such as substance use problems,^[9] problematic drugs or alcohol use,^[10][11] and substance use disorder.^[12][13] The National Institute of Mental Health (NIMH) states that "Substance use disorder (SUD) is a treatable mental disorder that affects a person's brain and behavior, leading to their inability to control their use of substances like legal or illegal drugs, alcohol, or medications. Symptoms can be moderate to severe, with addiction being the most severe form of SUD".^[14] Substance use disorders (SUD) are considered to be a serious mental illness that fluctuates with the age that symptoms first start appearing in an individual, the time during which it exists and the type of substance that is used.^[15] It is not uncommon for those who have SUD to also have other mental health 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.^[7] 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.^[7][16]

In the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (2013), also known as DSM-5, the DSM-IV diagnoses of substance abuse and substance dependence were merged into the category of substance use disorders.^[17][18] 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 International Classification of Diseases 11th revision (ICD-11) divides substance use disorders into two categories: (1) harmful pattern of substance use; and (2) substance dependence.^[19]

In 2017, globally 271 million people (5.5% of adults) were estimated to have used one or more illicit drugs.^[20] Of these, 35 million had a substance use disorder.^[20] An additional 237 million men and 46 million women have alcohol use disorder as of 2016.^[21] In 2017, substance use disorders from illicit substances directly resulted in 585,000 deaths.^[20] Direct deaths from drug use, other than alcohol, have increased over 60 percent from 2000 to 2015.^[22] Alcohol use resulted in an additional 3 million deaths in 2016.^[21]