Drugs can be categorized based upon their effects on users. There are essentially seven different drug types, each with its own set of characteristics, effects and dangers. Categories include stimulants, depressants, hallucinogens, dissociatives, opioids, inhalants and cannabis.

The 7 Types of Drugs

One of the most devastating truths about drug abuse is that it doesn’t just affect the person using it; it also affects their friends and families. Relationships can suffer, and trust may be broken throughout their substance abuse.

It’s difficult to pinpoint when recreational drug use triggers an outright addiction, but the physical and psychological risks of drug use are many. It’s important to understand the underlying causes of addiction — from prescription drug abuse to an attempt to self-medicate mental illness.

Article at a Glance:

There are many types of commonly abused drugs that can produce a variety of effects, each having risks associated with consuming them. These effects range from providing the person with energy to relaxing them and producing feelings of euphoria or happiness. There may be overlapping effects within the seven types of drugs. This overview discusses which specific drug classes create certain effects. The different types of drugs include:

  • Stimulants speed up the nervous system
  • Depressants slow down the nervous system.
  • Opioids create a sense of euphoria and are habit-forming.
  • Hallucinogens and dissociatives alter a person’s perception of reality.
  • Inhalants create a euphoric feeling, usually with household items ingested as gases or fumes.
  • Cannabis has depressant-like effects and also acts as a hallucinogen.


Stimulants or “uppers” impact the body’s central nervous system (CNS), causing the user to feel as if they are “speeding up.” These drugs increase the user’s level of alertness, pumping up heart rate, blood pressure, breathing and blood glucose levels.

Doctors primarily prescribe stimulants for ADHD and narcolepsy. The drugs can also help aid weight loss, as they can decrease appetite. Stimulant abuse can occur in school or college when students wish to enhance performance in school or sports.

Stimulants often come in pill form but are also consumed via snorting or even as food and drink. For example, caffeine is found in many beverages, and cocaine is a snorted powder.

Different types of stimulants include:

Risks of Stimulant Abuse

When abused, stimulants can cause a variety of undesirable consequences. These effects can include:


Among the most addictive types of drugs, opioids are powerful painkillers that produce a sense of euphoria. Derived from the poppy plant, opioids are often prescribed to patients who are suffering from intense pain. They are extremely habit-forming, and it may only take a couple of weeks to become physically addicted to these types of drugs. In some rare instances, studies have demonstrated that it is possible to become addicted after just one dose of an opioid

Opioids can be smoked, eaten, drank, injected or taken as pills. Examples of opioids include:

Risks of Opioid Abuse

Opioid abuse can devastate a person’s life. Unfortunately, when someone decides to stop using opioids, they may suffer tremendously. For example, opioid withdrawal can be especially difficult, riddling sufferers with flu-like symptoms. Other withdrawal effects include:

  • Nausea and vomiting
  • Diarrhea
  • Anxiety
  • Inability to sleep
  • Hot and cold flashes
  • Excessive sweating
  • Muscle cramps
  • Runny nose
  • Watery eyes


Like stimulants, depressants also impact the body’s CNS but with the opposite effect, making users feel as if things are “slowing down.” Thus, they are often called “downers” on the street.

Doctors prescribe some depressants for anxietyinsomniaobsessive-compulsive disorder and other medical issues that prevent the sufferer from fully relaxing. These drugs often offer a sedative experience, making them a tempting choice for teens and adults who wish to escape everyday stresses.

Examples of depressants include:

Alcohol as a Depressant

Alcohol acts as a depressant, making it a popular choice for people who need or want to relax. Although drinking is often associated with immediate bursts of energy, the person’s vital functions inevitably slow down. This slowing down can lead to slurred speech, altered judgment and unsteady movement. Overdosing on alcohol can cause severe toxicity and even death.

Tobacco as a Depressant

The active ingredient in tobacco is nicotine, a chemical that acts as both a stimulant and a depressant. Tobacco gives users a minor, immediate rush, followed by a feeling of relaxation. Nicotine is one of the most addictive substances available on the market and is dangerous to even try.

Risks of Depressant Abuse

Depressants can be useful when used properly, but depressant abuse can cause a host of issues in both the long and short term, including:

  • Confusion
  • Dizziness
  • Extreme sleepiness
  • Slowed heart rate
  • Difficulty speaking
  • Inability to concentrate
  • Lack of coordination
  • Labored or shallow breathing
  • Death


Hallucinogens are a class of drugs that alter a person’s perception of reality. They work by disrupting brain activity, affecting mood, sensory perception and muscle control. They can be made synthetically or found naturally. 

Although research is currently being conducted on medicinal uses for these drugs, most of these drugs are not prescribed and are considered recreational. Examples of hallucinogens include:

Risks of Hallucinogen Abuse

Hallucinogen abuse can have devastating effects that can last a lifetime:

  • Hallucinogen Persisting Perception Disorder, also known as flashbacks
  • Fear
  • Distorted cognition
  • Paranoia
  • Psychosis
  • Anxiety
  • Increased blood pressure
  • Nausea


Dissociatives distort the user’s perception of reality and cause people to “dissociate” or feel as if they are watching themselves from outside their own bodies. They may gain a false sense of invincibility then engage in risky behavior such as driving under the influence or having unsafe sex.

These drugs work by interfering with the brain’s receptors for the chemical glutamate, which plays a significant role in cognition, emotionality and pain perception. Dissociatives can be taken as liquids, powders, solids or gases. The drugs include:

Risks of Dissociative Abuse

Dissociatives are very dangerous, especially when used over extended periods of time. However, their immediate impact can be quite distressing as well:

  • Depression
  • Anxiety
  • Suicidal thoughts
  • Speech difficulties
  • Social withdrawal
  • Hallucinations
  • Detachment from reality
  • Numbness
  • Memory loss


Mostly made up of everyday household items, these drugs cause brief feelings of euphoria. As the name suggests, inhalants are always inhaled as gases or fumes. The “highs” slightly differ between inhalants, but most people who abuse inhalants are willing to huff whatever substance they can get.

Examples of inhalants include:

  • Fumes of markers, paint, paint thinner, gasoline and glue
  • Nitrous oxide
  • Aerosol sprays
  • Room deodorizers

Risks of Inhalant Abuse

Inhalant abuse can have devastating effects, both immediate and in the long run:

  • Loss of smell
  • Brain damage
  • Nosebleeds
  • Weakness
  • Euphoria
  • Increased heart rate
  • Loss of consciousness
  • Hallucinations
  • Slurred speech


Most commonly recognized as marijuana, cannabis acts like a hallucinogen but also produces depressant-like effects. It is a Schedule I drug (i.e., it has a high potential for addiction) but has increasing medicinal uses in the United States. Still, marijuana is often abused by those who do not medically require it.

Cannabis can be smoked, vaporized and even eaten if the THC is first rendered from the plant matter. Examples of cannabis include:

  • Marijuana leaves
  • Hashish
  • Hash oil
  • Cannabis-based medicines, such as Sativex

Risks of Cannabis Abuse

Despite being one of the most widely used types of drugs, cannabis abuse can destroy lives and have both short- and long-term impacts, including:

  • Lowered immunity to illness
  • Depression
  • Chronic anxiety
  • Reduced sperm count in men
  • Sedation
  • Slowed reaction times
  • Enhanced senses, such as seeing brighter colors
  • Impaired sense of time

More on Specific Drugs

No matter the type, all drugs have the potential to be dangerous. It is important to talk to your loved ones about drugs and how these substances can negatively impact their lives. We offer a number of free resources to help facilitate discussion, including our comprehensive Drug Index A-Z.

If you or a loved one struggles with drug abuse and addiction, we can help. The Recovery Village offers comprehensive, compassionate addiction treatment programs led by licensed medical professionals. Contact our helpful representatives to learn more, get your questions answered and start your road to lifelong recovery.

a woman with long brown hair smiling at the camera.
Editor – Abby Doty
Abby Doty graduated from Hamline University in 2021 with a Bachelor's in English and Psychology. She has written and edited creative and literary work as well as academic pieces focused primarily on psychology and mental health. Read more
a woman with long brown hair wearing a blue shirt.
Medically Reviewed By – Michelle Giordano
Michelle Giordano has been a licensed pharmacist in New York State for nearly two decades. She received her doctorate in pharmacology from St. John’s University, where she earned an academic merit scholarship throughout the course of her studies. Read more

National Institute on Drug Abuse. “What classes of prescription drugs are commonly misused?” July 16, 2021. Accessed February 22, 2022.

National Institute on Drug Abuse. “What Are Hallucinogens and Dissociative Drugs?” April 9, 2020. Accessed February 22, 2022.

National Institute on Drug Abuse. “What are inhalants?” July 16, 2021. Accessed February 22, 2022.

U.S. Drug Enforcement Administration. “Marijuana/Cannabis.” April 2020. Accessed February 22, 2022.

U.S. Drug Enforcement Administration. “Stimulants.” June 5, 2020. Accessed February 22, 2022.

Johns Hopkins Medicine. “The Science of Addiction.” Accessed February 22, 2022.

World Health Organization. “Clinical Guidelines for Withdrawal Manag[…]e in Closed Settings.” 2009. Accessed February 22, 2022.

Foundation for a Drug-Free World. “The Truth About Alcohol.” 2022. Accessed February 22, 2022.

Ashton, Heather; Millman, J. E.; Telford, Rosemary; and J.W. Thompson. “Stimulant and depressant effects of ciga[…]rain activity in man.” British Journal of Pharmacology, August 1973. Accessed February 22, 2022.

National Institute on Drug Abuse. “Prescription Depressant Medications.” December 9, 2021. Accessed February 22, 2022.

National Institute on Drug Abuse. “Hallucinogens and Dissociative Drugs Research Report.” April 9, 2020. Accessed February 22, 2022.

National Institute on Drug Abuse. “What are the other medical consequences of inhalant abuse?” May 20, 2020. Accessed February 22, 2022.

Medical Disclaimer

The Recovery Village aims to improve the quality of life for people struggling with substance use or mental health disorder with fact-based content about the nature of behavioral health conditions, treatment options and their related outcomes. We publish material that is researched, cited, edited and reviewed by licensed medical professionals. The information we provide is not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be used in place of the advice of your physician or other qualified healthcare providers.