What Is A Drug Class?

Drug classes organize substances into categories. There are many reasons why it is beneficial to do this. Drugs may be classified by the chemical type of the active ingredient. They are also organized by the effects of the drug.1 This can be particularly beneficial when using drugs for medical treatment or when treating addiction to a substance.

Drugs may also be classified under what’s called drug schedules. Drug schedules are used by lawmakers, law enforcers, and medical professionals to categorize controlled substances. This helps regulate these controlled substances, which can have harmful and addictive properties.

Drug Classes: Stimulants and Depressants


Stimulants are often known as “upper drugs.” They often cause effects such as increased alertness or energy. Stimulants may also cause other side effects such as:

  • Anxiety
  • Paranoia
  • Panic

Stimulants are frequently misused or abused since they seem like a mood booster. Students or young professionals often use them to help with work productivity or stay up all night to study.

Common stimulants include:

  • Cocaine
  • Adderall
  • Methamphetamine

When these drugs are taken regularly, a dependence may form, and they can be very addictive. Emergency room rates for stimulants have increased between 2004 and 2011 by nearly 15,000.2 Overall, there has been an increase in the use of stimulants. It’s cause for concern as these drugs can be addictive and cause harmful effects.


Depressants are often known as “downer drugs.” Depressants may cause drowsiness, reduce anxiety, calm muscle spasms, and prevent seizures. Drugs classified as depressants include:

  • Alcohol
  • Barbiturates
  • Benzodiazepines
  • Sleeping pills
  • Opioids

Depressants may be used to treat anxiety, pain, or as a sleep aid. At times, they are abused recreationally because they can have euphoric effects when taken in high doses. Depressants can become addictive and cause harmful effects, especially when misused or abused. And they are dangerous too. Depressants are responsible for more overdose deaths than stimulants.​​​3

Drug Classes: Hallucinogens and Opioids


Hallucinogens are drugs that:

  • Cause hallucinations
  • Create perceptual anomalies
  • Alter thoughts, emotions, and consciousness

Common hallucinogens include:

  • LSD
  • Psilocybin (also known as magic mushrooms or shrooms)
  • Peyote
  • DMT

Hallucinogens are often used recreationally. They produce euphoric and perceptual effects. A 2020 study found that 3.9 percent of high school seniors said they had used LSD in the past year.​​​4


Opioids are a class of drugs used to treat moderate to severe pain. Common opioids include:

  • Heroin
  • Fentanyl
  • Oxycodone (OxyContin)
  • Hydrocodone (Vicodin®)
  • Codeine
  • Morphine

Though doctors prescribe opioids for pain, people abuse them recreationally for the high that they create. Abuse of opioids has multiplied in recent years, and it’s caused an opioid epidemic in the United States.

According to the Center for Disease Control, “From 1999–2018, almost 450,000 people died from an overdose involving any opioid, including prescription and illicit opioids.”​​​5 These numbers are a major cause for concern and why many people are trying to bring awareness to this epidemic.

Drug Classes: Cannabinoids and Inhalants


Cannabinoids are a chemical compound found in cannabis (also known as marijuana). Marijuana can be used for recreational or medical purposes. Marijuana treats pain, anxiety, and inflammation. Marijuana is also used recreationally for the psychoactive effects it can have.

CBD (Cannabidiol) is one of the cannabinoids found in the cannabis plant. CBD products provide relief for anxiety, depression, and pain. Marijuana can be abused and can be psychologically addictive.

As marijuana is abused regularly, a tolerance will begin to build, requiring higher doses to get the same effects. Regular use of marijuana may also cause psychological addiction as someone may start to feel like they can’t function properly without the effects the drug provides for them. Like other drugs that affect your psychological state, marijuana can cause addiction, and treatment may be necessary.


Inhalants refer to the types of drugs that people can only take through inhaling. Common inhalants include:

  • Solvents
  • Aerosol sprays
  • Gases
  • Nitrites

Common effects that inhalants can have are:

  • Slurred speech
  • Lack of coordination
  • Euphoria
  • Dizziness

When taken in large doses, inhalants may also cause delusions or hallucinations. Adults are the least likely to abuse this substance. When abused over a long time, inhalants can become addictive. According to the National Institute on Drug Abuse, 8th graders are most likely to abuse this substance, at 6.1 percent abusing an inhalant in 2020.6

Many young people abuse inhalants because they’re easier to get than other substances. However, inhalants can be very dangerous and cause addiction.

Drug Classes: Steroids and OTC Medications


When thinking of steroids, many people associate them with anabolic steroids, synthetic versions of testosterone. Many athletes or bodybuilders use anabolic steroids to help build muscles. Using them this way is both illegal and can have dangerous effects.

Abuse of steroids mostly occurs with anabolic steroids. Abuse of anabolic steroids is generally seen in males between the ages of 18-40 who are trying to build muscle for sports or appearance reasons.

Though anabolic steroids are more commonly known, there is another type of steroid called corticosteroids. Corticosteroids are often used to treat arthritis, asthma, autoimmune diseases, and skin conditions. Steroids should only be used when medically necessary under the supervision of a medical professional.

Over-the-Counter Medication

Some over-the-counter medications may contain ingredients that have the potential for abuse. Two of the most common that are abused are dextromethorphan (DXM) and loperamide.

DXM is a cough suppressant found in many over-the-counter cold medications. When taken in higher doses, it can have a depressant and sometimes a hallucinogenic effect.

Loperamide is an anti-diarrheal medication. When combined with other drugs, such as prescription painkillers, Loperamide can an effect similar to opioids.

Side effects of misuse include:

  • Slurred speech
  • Poor motor control
  • Lack of energy
  • Increased blood pressure

People under the age of 18 often abuse over-the-counter medications because it can be easy for them to purchase these products rather than age-restricted or illegal substances. In 2020, 4.6% of 8th graders reported abusing the drug, while 3.2% of seniors reported the same.​​​7 These over-the-counter medications can become addictive if abused and can have many harmful effects. Like other drugs, addiction to over-the-counter medication requires proper treatment and support for recovery.


Drug classes are created to make it easier to organize and classify drugs. This can be beneficial for medical purposes or for treating addiction. Many of the drugs in these classes can have addictive properties. Someone who is struggling with addiction will require support and treatment for a full recovery. If you or someone you love is struggling with an addiction, there are resources available. Don’t wait to get help.