Some of these drugs are approved for certain medical uses. Other uses of these drugs are misuse. (Source: https://medlineplus.gov/)

• Opiates and other narcotics are powerful painkillers that can cause drowsiness, and sometimes intense feelings of well-being, elation, happiness, excitement, and joy. These include heroin, opium, codeine, and narcotic pain medicines (Oxycontin®, Percocet®, Fentanyl) that may be prescribed by a doctor or bought illegally.
• Stimulants are drugs that stimulate the brain and nervous system. They include cocaine, methamphetamine, and amphetamine. They also include non-amphetamine products used to treat attention deficit hyperactivity disorder. A person can start needing higher amounts of these drugs over time to feel the same effect.
• Depressants cause drowsiness and reduce anxiety. They include alcohol, barbiturates, benzodiazepines (Valium, Ativan, Xanax), chloral hydrate, and paraldehyde. Using these substances can lead to addiction.
• Hallucinogens: LSD, mescaline, psilocybin ("mushrooms"), and phencyclidine (PCP, or "angel dust") can cause a person to see things that are not there (hallucinations) and can lead to psychological addiction.
• Marijuana: Also known as pot, cannabis or hashish, marijuana is legal in some states for medicinal or recreational use; however, just like other legal drugs of abuse, using it can lead to addiction and other substance use concerns.
• Inhalants: Inhalants are volatile substances. They produce vapors that can be inhaled to make people feel different. Even though some substances in other categories can be inhaled, the substances called inhalants are rarely, if ever, taken any other way. Inhalants can be found in hundreds of legal products. There are four general categories of inhalants:
  • Volatile solvents, like paint thinners, drycleaning fluids, glue, and felt-tip markers
  • Aerosols, like hair sprays, vegetable oil sprays, and fabric protector sprays
  • Gases, like nitrous oxide in whipped cream dispensers
  • Nitrites, chemicals used in air fresheners, leather cleaners and nail polish
• Club drugs: Club drugs are group of psychoactive drugs. They act on the central nervous system and can cause changes in mood, awareness, and behavior. These drugs are most often used by young adults at bars, concerts, nightclubs, and parties. Club drugs, like most drugs, have nicknames that change over time or are different in different areas of the country. The most commonly used club drugs include:
  • MDMA (Methylenedioxymethamphetamine), also called Ecstasy and Molly
  • GHB (Gamma-hydroxybutyrate), also known as G and Liquid Ecstasy
  • Ketamine, also known as Special K and K
  • Rohypnol, also known as Roofies
  • Methamphetamine, also known as Speed, Ice, and, Meth
  • LSD (Lysergic Acid Diethylamide), also known as Acid

Some of these drugs are approved for certain medical uses. Other uses of these drugs are misuse. (Source: medlineplus.gov/clubdrugs.html)

An opioid is a drug that helps stop pain. Opioids include medicine that people get with a prescription, like fentanyl, oxycodone (OxyContin®), hydrocodone (Vicodin®), codeine, and morphine. They also include drugs like heroin. 

Whether people get a prescription for opioids or get the substances another way, they can be at risk for OUD. OUD is the use of opioids to the point of harm or distress. Formerly called opioid addiction, opioid abuse, or opioid dependence, OUD occurs when opioid use causes significant impairment and distress. A diagnosis of OUD is based on specific criteria such as unsuccessful efforts to cut down or control use or use resulting in a failure to fulfill obligations at work, school, or home, among other criteria.