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What are Drug Classifications?

Understating drug classifications is vital if you want to begin your recovery journey. Learn more about the relevant classifications here.

What are Drug Classifications?

Drug classifications are simply a way of organizing drugs that share some similarities into their own categories. The concept became popular thanks to Title II of the Controlled Substances Act (CSA), which separated drugs further into schedules or classes, making it easier to classify them for general use.

Individuals facing challenges with substance use disorder should particularly understand and pay attention to drug schedules and the classification of drugs. For example, a Schedule I drug has a high abuse rate compared to a Schedule V with low risks. 1

What Is the Drug Classifications Chart?

Before the CSA Act was created in the 1970s, drugs were not organized or classified using the schedule of drugs. A drug classification chart is a helpful tool that outlines some of the commonly misused drugs.

Since the inception of the CSA Act, drugs have been added, removed, or reclassified to a different schedule. It is quite uncommon for a controlled drug to be recategorized, but there have been recent requests to get marijuana to at least a Schedule III from Schedule I drug.

What Is the Purpose of Drug Classifications?

The main purpose of drug classification is to determine which drugs are meant for medical use and which are not. With drug classification, people can protect themselves from severe physical or psychological effects, especially when taking new medication.

How Many Drug Classifications Are There?

There are up to seven different drug classifications. However, they are split into three main drug classifications based on chemical makeup, effects, and legal definition. The tricky thing with drug classification is that some drugs are in multiple drug classes with the same classification. At the same time, some drugs can be under one classification but may not be together under another.

Drug Classifications by Chemical Makeup

drug classifications   

The similarity of a drug’s chemical makeup is a vital factor to consider. When classifying drugs, they can often pose the same risks and impact. An individual suffering from substance use disorder is likely to consume drugs with chemical similarities. The drugs also share identical effects when seeking treatment.


Alcohol is one of the most consumed drugs globally, with 60% of the American population consuming alcoholic beverages on a regular basis. The drug is legal in almost every place and has many effects on the individual. Short-term effects include impaired reaction time and lapses in judgment and perception. Some of the long-term effects of alcohol include liver damage. 2


Opioids are drugs manufactured from the poppy plant, or from chemicals that mimic the plant. Opioids are a large and steadily growing problem in America. The drug attaches itself to the brain's neurotransmitters, effectively blocking out signals. They are prescribed as a painkiller but are also highly addictive and readily available in other forms as well. Some of the common opioids include oxycodone, heroin, and fentanyl. 3


Benzodiazepines are used to treat different mental disorders and sleeping conditions. Roughly thirty million US adults have used benzodiazepines at one point in their life. The drug functions by coming into contact with the GABA-A (gamma-aminobutyric acid-A) neurotransmitter. Each benzodiazepine interacts with the mind and body differently, so they are often misused. Some examples of this type of drug include Xanax, Ativan, and Valium. 4


Cannabinoids are the second-most abused drug class, with 18% of US adults claiming to have used them at least once. The drug class has a similar chemical composition to tetrahydrocannabinol (THC). It features the same effects evoking feelings of happiness but poses both physical and mental risks. Cannabinoids are becoming legal in most states after scientific proof emerged of their medical use. 5


The drug is a by-product of barbituric acid and is known for slowing down the central nervous system. They're commonly used for treating sleeping issues and mental disorders, among other health complications. Barbiturates are highly addictive and can even make the body system shut down. Almost half of a million Americans claim to have used the drug. Examples of the drug include pentobarbital, Amytal, luminal, and others. 6

Drug Classifications Based on Effects

Drugs are also classified depending on how they affect a person's mind and body. For example, one drug can make someone feel energetic, while another can make them feel calm. Every drug will affect the body differently and will also affect every individual in varying ways.


Also known as “downers,” depressants evoke the feeling of tiredness and, at the same time, relaxation. The drugs are highly effective for mental disorders and sleeping issues, but they are also highly abused due to the buzz or high they create. Depressants can be extremely dangerous, and regular abuse often leads to overdose. Some common depressants include barbiturates, alcohol, and opiates.


In contrast to depressants, stimulants increase focus, energy, and wakefulness. These are commonly referred to as “uppers.” When used in a controlled manner, the drugs increase the individual's productivity. However, long-term abuse of stimulants can lead to addiction. Examples of common uppers are meth, cocaine, and Adderall.


These drugs alter the person's view of reality. Hallucinogens are mostly known for their visual and auditory hallucinations. While they are less addictive than other drug type classifications, their fast-acting side effects tend to be more severe. Examples of hallucinogens include psilocybin mushrooms, PCP, and LSD.


Inhalants are consumed by inhaling chemicals from various products. Most inhalants were not meant for human consumption, though they produce a high feeling. These drugs are not as well researched and documented as other classifications, but they can still lead to severe health complications. Common inhalants include gasoline, paint thinners, and nail polish removers.

Drug Classifications by Legal Definitions

The drug enforcement agency (DEA) enforces the full comprehensive drug classification chart in the Code of Federal Regulations. Here is a legal drug classification list of the various drug classification schedule levels.

  • Schedule I Drug: These have no medical function and often pose a high risk of abuse. These drugs include heroin, bath salts, LSD, peyote, marijuana, methaqualone, ecstasy, and others. 
  • Schedule II Drug: These drugs are known for their high potential for abuse and severe physical or psychological dependence. Despite the high risk of misuse, the drugs also have proven medical uses and can usually only be obtained with a prescription. These include drugs like cocaine, methamphetamine, hydrocodone, fentanyl, or Adderall.
  • Schedule III Drugs: This level includes drugs with moderate to low risks of psychological and physical dependence. However, they still pose a threat if used wrongly. The level includes codeine, anabolic steroids, suboxone, and ketamine. 
  • Schedule IV Drugs: This is a category of drugs with a very low potential for dependence and misuse since they have specific medical uses. They do, however, pose a high psychological or physical risk when consumed with other drugs like alcohol. This includes drugs like Xanax, tramadol, Soma, Ambien, and Valium.
  • Schedule V Drugs: In comparison to Schedule IV drugs, these have an even lower risk of abuse and dependence. They include Parepectolin, Robitussin AC, Lyrica, Lotil, Motofen, among others.[7]

Find Recovery for Drug Addiction in San Diego

classification of drugs

Located in San Diego, the Genesis Recovery drug and alcohol abuse rehab center can help you or your loved ones recover from various drug addictions. The center specializes in addiction treatment and dual diagnosis through its four key elements: multi-faceted practices, clinical help, 12-step zero-tolerance programs, and community work as well.

Knowing the drug classifications before taking any drug can help you to figure out what the level of potential abuse may be, and can better equip you to know what to expect. They are helpful to know about even after you or a loved one start using a certain drug as well, just to know how the drug you’re taking can interact with other substances as well. Knowing and using this knowledge can help keep you and your loved ones safe.  

Contact Genesis Recovery Today

Get started on the road to living a better, healthy life by contacting us today and getting the help you or a loved one might need.


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