<unk>  (OUD) is a substance use disorder relating to the use of an<unk> . Any such disorder causes significant impairment or distress. Signs of the disorder include a strong desire to use<unk> s, increased tolerance to<unk> s, difficulty fulfilling obligations, trouble reducing use, and withdrawal symptoms with discontinuation.<unk>  withdrawal symptoms may include nausea, muscle aches, diarrhea, trouble sleeping, agitation, and a low mood. Addiction and dependence are components of a substance use disorder. Complications may include<unk>  overdose, suicide, HIV/AIDS, hepatitis C, and problems at school, work, or home.<unk> s include substances such as heroin, morphine, fentanyl, codeine, dihydrocodeine, oxycodone, and hydrocodone. In the United States, a majority of heroin users begin by using prescription<unk> s that may also be bought illegally. Risk factors for misuse include a history of substance use, substance use among family and friends, mental illness, low socioeconomic status, and race. Diagnosis may be based on criteria by the American Psychiatric Association in the DSM-5. If more than two of eleven criteria are present during a year, the diagnosis is said to be present. Individuals with an<unk>  are often treated with<unk>  replacement therapy using methadone or buprenorphine. Being on such treatment reduces the risk of death. Additionally, individuals may benefit from cognitive behavioral therapy, other forms of support from mental health professionals such as individual or group therapy, twelve-step programs, and other peer support programs. The medication naltrexone may also be useful to prevent relapse. Naloxone is useful for treating an<unk>  overdose and giving those at risk naloxone to take home is beneficial. In 2013,<unk> s affected about 0.4% of people. As of 2016, about 27 million people are affected. Long term<unk>  use occurs in about 4% of people following their use for trauma or surgery-related pain. Onset is often in young adulthood. Males are affected more often than females. It resulted in 122,000 deaths worldwide in 2015, up from 18,000 deaths in 1990. In the United States during 2020 alone, there were more than 65,000 deaths due to<unk>  overdose, of which more than 15,000 were the result of heroin use.
Opioid use disorder
Alcoholism
Stimulant use disorder
Benzodiazepine use disorder
Cannabis use disorder
Benzodiazepine dependence
Amphetamine dependence
Cocaine dependence