Hard drugs and alcohol on an old wooden table

One of the strongest weapons in the fight against drug abuse and addiction is knowledge. The more we understand addiction and how different drugs can lead to it, the more opportunities we have to fight against it. There are four types of drugs, classified by the effect they provide when used.

What Are the Four Classifications?

The term “drug” encompasses an incredible amount of substances, including medications such as ibuprofen that don’t see abuse. Addictive drugs commonly abused tend to alter the way our mind handles sensations and stimuli. This requires changes to our central nervous system, the severity of which is determined by the chemical makeup of the drug in question.

A quick note to make is that these classifications of the four types of drugs are used in a medical and scientific manner. The United States federal government has a separate scheduling system based on the strength of a drug and its effects on the physiology, cognition and mental acuity of its users. Illicit drug use comes with possession of illegal drugs, leading to criminal charges in most states.

Grouping Drugs Based on Effect

Many drugs that are considered addictive or habit forming are safely prescribed to patients every day. For many of us, this is the extent of drug use as it ends with the prescription. Unfortunately a large number of patients end up becoming addicted to prescription medications, even if taken as directed.

Whether legally obtained or not, addictive drugs are classified as one of the following:

  • Opioids
  • Stimulants
  • Depressants
  • Hallucinogens

Each of these four classifications will interact differently with the user, changing how they behave both internally and externally.

Natural and Synthetic Opioids

You’ve likely heard the term “Opioid Epidemic” thrown around on the news or online. Opioids are the set of drugs derived from the poppy plant, the source of opium. Typically these are prescribed to treat moderate to severe pain for both recovery and chronic pain. Opioids block pain by sealing off the receptors that trigger the sensation.

Opioids also provide a sense of euphoria in users along with heavy sedation. These are the effects sought out by those illegally using opioids. The effects diminish over time, requiring more opioids to achieve the same effect which can cause a lethal overdose.


Used to treat ADHD and narcolepsy, stimulants provide a boost to the central nervous system’s operating capacity. Caffeine is considered to be the most widely used stimulant in the world which makes sense as many of us can’t start the day without a bit of coffee. It increases wakefulness and focus, but at the cost of dependencies being developed in the brain.

As dependencies and a tolerance build, larger quantities of stimulants are taken to compensate. A stimulant overdose often manifests as heart attack, stroke and even seizures. Illegal drugs associated with stimulant overdose include cocaine, methamphetamines and ecstasy. Prescription stimulants such as Adderall and Ritalin are popular among students and those in high-pace work environments.


The opposite of stimulants, depressants actually inhibit the central nervous system’s ability to process information. The firing of neurons is slowed to reduce intrusive thoughts, providing a sense of relaxation. Ideal for those with chronic anxiety or trouble sleeping, depressants are heavily abused by those looking to self-medicate without a valid prescription.

Depressant abuse can lead to side effects that make it difficult to interact with the world around you. Simply maneuvering around the house becomes impossible due to dizziness and a total lack of coordination. If stumbling through a room sounds like a familiar experience, it’s likely due to the fact that alcohol is the most common depressant used. That drunken feeling you get is due to the depressant nature of the drink.


As the name suggests, hallucinogens change how we perceive the world around us. Hallucinations and changes to how the mind interprets external stimuli are trademarks of hallucinogens. Colors, sounds, movement and time are all experienced in an altered state of mind. Hallucinogens can even lead to dissociation, otherwise known as an out-of-body experience.

Hallucinogens tend to have the most variation in how it impacts the user in regards to how significant the changes to reality are. LSD, mescaline and psilocybin, or magic mushrooms, are common hallucinogens consumed in the United States.

If you have any questions about the above drugs or drug addiction, reach out to America’s Rehab Campus for a free consultation today.