Psychoactive drugs are chemical substances that change a person’s mental state. They do this by affecting the way the brain and nervous system work. Changes in brain function due to psychoactive drug use can affect a person’s perceptions, moods, and/or consciousness.
Also called psychotropics, psychoactive drugs can lead to intoxication. This is often the primary reason that people choose to take these types of substances.
Psychoactive substances are found in a number of medications as well as in alcohol, illegal and recreational drugs, and some plants and even animals. Alcohol and caffeine are psychoactive drugs that people most commonly use to alter their mental state. These drugs are legally available, but can still be physically and psychologically harmful if taken to excess.
Usually, people decide when and how they want to use psychoactive drugs. 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 taking prescribed psychoactive drugs in ways other than intended, for example, taking drugs that have been prescribed for someone else, even if they have been given to you, is illegal.1
Natural substances, such as hallucinogenic mushrooms and cacti, and the leaves, flowers, and buds of certain plants may also be psychoactive.2 Some people think that, because these substances occur naturally, they are less harmful than manufactured drugs. However, that is not the case.
For example, someone who uses a psychoactive plant to alter their mental state may have a higher risk of overdose or poisoning.
The reason for this is because the person taking the substance has no control over the strength of the plant’s psychoactive substance or toxicity, as there is in manufactured drugs. The same is true of street drugs purchased from a drug dealer, which are typically cut with a variety of other psychoactive and filler substances, some of which may be harmful.
A drug or medication that’s termed “psychoactive” isn’t necessarily addictive, although many are.
There are several ways in which psychoactive drugs are classified:
- By their common effects (effects they all have) in the brain and body—for example, stimulants and depressants
- 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)3
Groups of psychoactive drugs include stimulants, depressants, narcotics (opioids), hallucinogens, and marijuana (cannabis).
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 even death.4
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.5
Examples of depressants include alcohol and tranquilizers such as benzodiazepines.
These are derived from the poppy plant (opiates) or synthetically produced (opioids). Examples of their effects include pain relief, drowsiness, euphoria, confusion, and respiratory depression.
With excessive use, effects may include nausea and vomiting, convulsions, respiratory arrest, coma, and death.6
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, and depression.7
Examples of hallucinogens include psilocybin from mushrooms, “acid” (LSD), ketamine, phencyclidine (PCP), dextromethorphan, and peyote (mescaline).
Examples of the psychoactive effects of marijuana include changes in sensory perception; euphoria; relaxation; appetite changes; impaired memory, concentration, and coordination; and changes in blood pressure.8 Marijuana is the only drug in its class.
Designer drugs, formerly known as “legal highs,” are chemicals that are produced to mimic the effects of other psychoactive substances such as stimulants, hallucinogenics, sedatives, or a combination.9 As their chemical composition is often unknown and evolving, they present clear challenges to toxicologists, medical staff, and society. They include bath salts, mephedrone, W18, MXE, spice, and many others.