What Does "Psychoactive" Mean?

Learn About 5 Groups of Psychoactive Drugs

woman drinking bloody mary cocktail
Alcohol is the psychoactive drug people most commonly use to alter their mental state. Doug Schneider Photography/Photolibrary/Getty Images

"Psychoactive" (also called "psychotropic") is a term that is applied to chemical substances that change a person's mental state by affecting the way the brain and nervous system work. (This can lead to intoxication, which is often the main reason people choose to take psychoactive drugs.) The changes in brain function experienced by people who use psychoactive substances affect their perceptions, moods, and/or consciousness.


Psychoactive substances are found in a number of medications as well as alcohol, illegal and recreational drugs, and some plants. Alcohol is the psychoactive drug people most commonly use to alter their mental state.

In some situations, however, psychoactive drugs are used to alter someone's mental state in order to exploit the person. A common example of this is the date-rape drug Rohypnol (which is illegal in the U.S.). You should also be aware that abusing prescribed psychoactive drugs is illegal.

Natural substances, such as hallucinogenic mushrooms and cacti, and the leaves, flowers, and buds of certain plants may also be psychoactive. Some people think that, because these substances occur naturally, they are more acceptable than manufactured drugs. However, that's not the case. Someone who uses a psychoactive plant to alter his or her mental state may have a higher risk of overdose or poisoning.

Why? Because there's no control, as there is in manufactured drugs, over the strength of the plant's psychoactive substance or toxicity.

A drug or medication that's termed "psychoactive" isn't necessarily addictive, although many are.

How Are Psychoactive Drugs Classified?

There are four ways in which psychoactive drugs are classified:

  • By their common effects (effects they all have) in the brain and body -- for example, antidepressants, hypnotics (sleep aids), and medications used to treat conditions such as attention deficit hyperactivity disorder (ADHD)
  • By their likelihood to cause addiction (high to low)
  • By their chemical structure
  • By U.S. Drug Enforcement Administration schedules I-V, which classify these drugs by the potential for abuse ("I" is highest, "V" is lowest)

This article provides detail on psychoactive drugs' common effects.

The five groups of psychoactive drugs are stimulants, depressants, narcotics, hallucinogens, and, in its own category, marijuana (cannibis).

Stimulants. Examples of effects include heightened alertness, greater energy, excitability, improvement in mood that can reach euphoria, and bodily responses such as increased heart rate and blood pressure. 

Examples of stimulants include caffeine, nicotine, amphetamines, and cocaine. Examples of the effects of excessive use of cocaine may include irritability, mood swings, hallucination, heart palpitations, chest pain, and death.

Depressants. Examples of effects include reduced feelings of tension, relief of anxiety, and muscle relaxation. With excessive use, effects may include clammy skin, slow and shallow breathing, a rapid and weak pulse, coma, and death.

Examples of depressants include alcohol and tranquilizers such as benzodiazepines and barbiturates.

Narcotics. Almost all the drugs in this group are derived from morphine. Examples of their effects include pain relief, drowsiness, euphoria, confusion, and respiratory depression (slowed breathing that keeps the lungs from expanding fully and providing enough oxygen to the body).

With excessive use, effects may include nausea and vomiting, convulsions, respiratory arrest, coma, and death.

Examples of narcotics include codeine, morphine, oxycodone, and heroin.

Hallucinogens. Examples of effects include paranoia, depersonalization (a sense of not being real), hallucinations, erratic behavior, and increased blood pressure and heart rate.

Effects of excessive use may include problems thinking and speaking, memory loss, depression, and weight loss. Medical emergencies seldom occur. 

Examples of hallucinogens include psilocybin from mushrooms, "acid" (LSD), ketamine, phencyclidine (PCP), dextromethorphan, and peyote (mescaline).

Marijuana (cannibis). Marijuana is often "lumped" with the narcotic drugs because of its effects, but it isn't one either legally or pharmacologically. Examples of effects include enhancement of one's senses; euphoria; relaxation; appetite changes; impaired memory, concentration, and coordination; and blood pressure reduction. Marijuana is the only drug in its class.


“Psychoactive drugs and their classifications.” North Seattle (WA) College/Faceweb.NorthSeattle.Edu (2016).

"Word of the day: psychoactive drugs." National Institute of Drug Abuse, National Institutes of Health (2016).

"Drugs of abuse." U.S. Drug Enforcement Administration (2011).

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