Drug Classifications & Categories

Drug Classifications & Categories

Controlled substances, in the United States, are categorized based on their medical value and their correlative risk for abuse. These drug classifications are known as “schedules.”

In the past, US had more than 200 various drug laws which made it quite difficult and complicated for law enforcers. In the late 1960’s, since there was a sudden increase in crime and drug use, national studies were started and these linked the crime rate to drug addiction. As a result, the government launched the War on Drugs.

The first legislation which was enacted to provide a legal basis to the said war is the Comprehensive Drug Abuse Prevention and Control Act. The said act merged all the existing federal drug statutes into one law to make prosecution of drug cases easier and faster.

The most significant part of the said Act is Title II which is known as the Controlled Substances Act (CSA). This Act regulated drugs by segregating them into classes called “schedules.”

All these classifications, except anabolic steroids, belong to the psychoactive types because these are known to affect the brain and make changes on one’s feelings, moods, thoughts, memory, mental processing, discernment, and behavior. Aside from that, these drugs are linked to a multitude of mental conditions, physical health issues, and even personal problems like psychosis due to cannabis, social stigma, liver cirrhosis, and even financial troubles and legal issues.

What are Drug Classifications?

Chemically, drugs are segregated and categorized based on their effects on the body and to the brain. The most common chemical classifications are opioids, hallucinogens, stimulants, and depressants. In addition to this, the DEA also made a legal classification of drugs and they grouped the same according to schedules. The basis for this drug scheduling scheme is the drugs medical value and its risk for dependence and abuse.

Drugs can be grouped and classified in various ways. In medicine and pharmacology, drugs are sorted based on their chemical activities and on their respective treatment conditions. Mucolytic are drugs which relieve respiratory congestion by breaking down mucus while anticonvulsant drugs are used to deal with seizures.

If we talk about drug addiction and rehab, the following drug classifications are used more frequently: Anabolic steroids, Depressants, Hallucinogens, Narcotics, Stimulants.

All these classifications, except anabolic steroids, belong to the psychoactive types because these are known to affect the brain and make changes on one’s feelings, moods, thoughts, memory, mental processing, discernment, and behavior. Aside from that, these drugs are linked to a multitude of mental conditions, physical health issues, and even personal problems like psychosis due to cannabis, social stigma, liver cirrhosis, and even financial troubles and legal issues.

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Drug Classification Based on Chemical Makeup

There are numerous classes of drugs, but one of the most common classifications is based on its chemical components. Though these drug types are manufactured for different specific purposes, the compounds that made it up results to one effect – the creation of euphoric feelings.

The compounds that made up this drug interacts with the brain’s neurotransmitters in various ways and lead to feelings of pleasure, relaxation, and sedation. Then again, opposite these “feel good” effects and sensations are negative effects on one’s mental faculties, psychological condition, the perception of reality, and physical well-being.

Below are five major classes of drugs according to chemical make-up:


According to DrugAbuse.gov, though drinking alcohol is not really a problem, drinking too much of it could lead to dangerous, if not deadly, consequences. It is the most widely used and abused substance not only in the United States but worldwide. Furthermore, according to a study published by NCADD, drinking alcohol gives a euphoric feeling to the individual, thus also lessening his inhibitions.


These types of drugs act by attaching themselves to the brain’s neurotransmitters and leads to a flooding of euphoric feelings. They are considered one of the most prescribed drugs for treating pain. Examples of opioids are the following:

  • Buprenorphine
  • Codeine
  • Fentanyl
  • Heroin
  • Hydrocodone
  • Methadone
  • Morphine
  • Oxycodone


These types of drugs have the same chemical composition and make-up with tetrahydrocannabinol (THC), the known potent compound in marijuana. Taking these types of drugs would lead to elated feelings, commonly known as “high,” but would likewise result in adverse physical and mental functioning. Examples of cannabinoids are marijuana and hashish.


Commonly known as Benzos, these drugs interact differently with each of the brain’s neurotransmitters called gamma-aminobutyric acid-A (GABA-A) and influences the mind and the body in different ways as well. These drugs are used and prescribed to address sleep problems and psychiatric conditions. However, if not used as intended, it is highly addictive.


Barbiturates affects one’s central nervous system by decelerating its functions. These are known treatments for sleep disorders and other psychiatric conditions. Even it is valuable as anesthesia and treatment for headaches and epilepsy, if taken in high doses, could lead to addiction and shut down of the body system. These are a few examples of this drug type — Luminal, Amytal, and Pentobarbital.

Drug Classification Based on Effect

Dependence and frequent use of psychoactive drugs can cause substance abuse because these types of drugs stimulate the brain’s reward system. Though the brain’s reward system has evolved naturally to boost behaviors that are essential for survival, it can be lethal if applied in use and dependence on addictive substances.

In the recent Surgeon General’s Report, it was stated that drugs impact the brain’s reward system in a such a way as encouraging repetitive usage because of the flow of dopamine that creates euphoric feelings of pleasure. Addiction will ensue if drugs seize and take charge of the brain’s reward system.

These are the types of regulated drugs that interact with the central nervous system and alter one’s perceptions and emotions:


Depressants are drugs which overpower or slow down the brain and nerve activity by acting on the central nervous system and produce a restful or numbing feeling. Examples of depressants include the following:

  • Alcohol
  • Barbiturates (butalbital, phenobarbital, and thiopental)
  • Benzodiazepines (alprazolam, diazepam, and midazolam)
  • Gamma-hydroxybutyrate (GHB)


These are the types of drugs that hasten the actions of one’s central nervous system. Stimulants may make the individual feel alert, energetic, and focused. On the other side of the coin, this same drug class can make you feel angry, jittery, and even paranoid. Based on UN’s World Drug Report, next to marijuana, stimulants derived from amphetamine, like ecstasy, are the most frequently abused substance around the world.


This drug class is more commonly known as psychedelics and interacts with one’s central nervous system to modify one’s perception of space, time, and the world. Being such, it can result in seeing and hearing things that don’t really exist in reality. Examples of this drug class are lysergic acid diethylamide, peyote, psilocybin, and dimethyltryptamine.


This drug class is composed of a wide array of drugs which are consumed through inhalation. Almost all substances falling under this class appears in gas/vapor format. These substances reach the bloodstream through the lungs and the modes of abuse can vary. Common types of abuse methods include spraying, sniffing, inhaling, bagging, and huffing.

Drug Classifications Based on Legal Definitions

According to the United States Drug Enforcement Association, chemicals (that made up the drug), substances, and drugs are categorized into five (5) different groups (schedules) based on the drug’s medicinal value and its correlative potential for dependency and abuse.

The specific drug’s abuse rate is the major determinate aspect for drug scheduling. For instance, Schedule I have more risk for abuse and are equally high in creating severe physical and psychological dependence. Schedule V, on the other hand, poses a lesser risk of abuse and also create less severe physical and psychological dependence.

Below are the specific drug schedules with their corresponding descriptions:

Schedule V:

This particular drug schedule is made up of drugs that pose low risk/potential for dependence and abuse relative to drugs in Schedule IV. Being such, drugs in this schedule are currently accepted for therapeutic use for treatments. Abuse of drugs in this schedule can result in partial physical addiction or in limited psychosomatic dependence. Examples of drugs in this class include diphenoxylate (when mixed with atropine), and pregabalin. This specific drug class is composed of drugs that show low risk/potential for dependence and abuse and are presently accepted for medical use in treatment relative to drugs in Schedule III. Abuse of this drug may cause limited physical addiction or psychosomatic dependence. Drugs in this schedule include benzodiazepines, tramadol, and modafinil.

Schedule III:

Schedule III drug types include those drugs that show a risk/potential for abuse, in lesser effects compared to drugs and substances in Schedules I and II. Also, these drugs are presently recognized for its medical use in various medical treatments. Abuse of this drug type can result in moderate or low physical dependence or high psychosomatic addiction. Examples of Schedule III drugs include ketamine, anabolic steroids, and buprenorphine.

Schedule II:

Schedule II drugs are known to pose a high risk for abuse. Also, they are medically accepted to be used for treatments, but with severe restrictions. Abuse of this drug type can lead to severe physical and psychological addiction. Examples of the drug in this category include cocaine, amphetamine, fentanyl, hydrocodone, and hydromorphone oxycodone.

Schedule I:

Of all the drug schedules, this category of drugs pose a high risk/potential for abuse. Presently, this drug type doesn’t have any medical use and value and abuse of the same can lead to deadly and toxic effects. Also, there are no known safety guidelines for use of this drug, even under medical supervision. Examples of the drug in this category include ecstasy, cannabis, heroin, GHB, mescaline, LSD, and methaqualone.

Start the Admission Process Now

If you or a loved one is struggling with substance abuse, now is the right time to take action. Don’t let addiction take away your joy, your relationships, and your life. You have a way out of addiction. Go to a trusted addiction rehab center and speak to an Addiction Specialist. They know how to help you cope with addiction and its ill effects on your mind, body, and life.

If you’re adamant you will get the right treatment that you need, ask your Addiction Specialist for treatment options. There are various ways to deal with addiction and you can choose which of these ways you are most comfortable with.

If financing your rehab is a major obstacle for your decision to get help, don’t worry. Your Addiction Specialist can also help you find cost-effective ways of financing your rehabilitation treatment program.

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