Substance Use Disorders
The medical world currently views substance use disorder according to the class of drug that is used. As a result, it defines 10 separate substance use disorders. All of the disorders share the defining features of addiction—they directly and intensely activate reward and reinforcement systems of the brain, stimulating compulsive use that typically leads to the neglect of normal activities and negative consequences. With some variation, they also share common symptoms, although withdrawal symptoms differ significantly among them and do not occur for some classes of drug (hallucinogens and inhalants).
- Alcohol Use Disorder: Alcohol is a brain depressant and alcohol use disorder is common, more so among adult men (12.4 percent) than among women (4.9 percent), although it is on the rise among women. It affects men and women differently; women seem to be more susceptible to some of the detrimental effects of alcohol, researchers find. Most commonly, the disorder develops well before age 40.
- Caffeine Intoxication: The consequence of very high doses of caffeine consumption, caffeine intoxication is marked by symptoms including restlessness, nervousness, insomnia, flushed face, gastrointestinal disturbance, muscle twitching, rambling thoughts and speech, cardiac rhythm disturbances, periods of inexhaustibility, and psychomotor agitation.
- Cannabis Use Disorder: Cannabis use disorder is highest among 18- to 29-year-olds (4.8 percent) and prevalence of the disorder decreases with age.
- Phencyclidine and Other Hallucinogen Use Disorder: These substances alter perception. Phencyclidine is commonly called “angel dust” or PCP and produces feelings of separation of mind from body.
- Inhalant Use Disorder: Inhalant substances are volatile hydrocarbons, toxic gases that are released from glues, fuels, paints and other volatile compounds and have psychoactive effects. The disorder occurs primarily among those ages 12 to 17.
- Opioid Use Disorder: Opioid drugs include the illicit drug heroin and prescription pain-relievers such as oxycodone, codeine, morphine, and fentanyl, among others. According to the American Society of Addiction Medicine, in 2015, 2 million people had a substance use disorder involving prescription pain relievers and 591,000 had a substance use disorder involving heroin. Opioid-related overdoses are now the leading cause of death in Americans under 50 years of age. Prescribed opioids are the “overwhelming initial source” of addiction.
- Sedative, Hypnotic, or Anxiolytic Use Disorder: Addiction to sleeping pills and anti-anxiety medications falls into this category. Like alcohol, these agents are brain depressants. Rates of the disorder are highest among 18- to 29-year-olds.
- Stimulant Use Disorder: Substances in this group include amphetamines; methylphenidate, best known as the prescription drug Ritalin; and cocaine. Stimulant drugs are commonly prescribed for the treatment of attention-deficit hyperactivity disorder (ADHD) and narcolepsy. In the U.S., cocaine use is highest among those aged 18 to 25.
- Tobacco Use Disorder: The nicotine in tobacco acts as a central nervous system stimulant. Studies show that 68 percent of adult smoker want to quit, and 50 percent of smokers have made attempts to quit.
- Other (or Unknown) Substance Use Disorder: Substances ranging from antihistamines, betel nut, and cortisol to steroids may also have effects on the central nervous system that lead to compulsive use causing serious problems.