Skip over navigation

States of Consciousness

Altered States


Quick Review

Some states of consciousness don’t occur naturally and must be induced in some way. These include hypnotic states, meditative states, and drug-induced states.


Hypnosis is a procedure that opens people to the power of suggestion. A hypnotist puts a subject in an altered state by encouraging relaxation and sleepiness and often describing the sorts of physical sensations a subject should be feeling. Once a subject is in the altered state, he or she may act, perceive, think, or feel according to the hypnotist’s suggestions. Not everyone can be hypnotized, and some people are more hypnotizable than others. The following chart shows what hypnosis can and can’t do.

Hypnosis can: Hypnosis can’t:
Cause people to be relaxed, have a narrowed focus of attention, and be highly engaged in fantasies Work equally effectively for everyone
Produce anesthesia and treat a range of psychological and medical problems Force people to do things against their will
Cause hallucinations and distortions in sensory perception Make people act in ways that would normally be beyond their physical or mental abilities
Reduce inhibitions Reliably increase the accuracy of memories
Cause changes in behavior after the hypnosis has ended Allow people to actually reexperience past events or lives

If hypnotized people are instructed to forget what happened during hypnosis, they later claim to have no memory of it. This phenomenon is called posthypnotic amnesia.

A hypnotic state isn’t sleep—brain waves, for example, do not reliably change during hypnosis as they do during sleep. Researchers don’t even agree that hypnosis is an altered state of consciousness. Researchers propose two main theories about hypnosis:

  • Ernest Hilgard proposed that hypnosis causes people to dissociate or divide their consciousness into two parts. One part responds to the outside world, and the other part observes but doesn’t participate. According to this theory, hypnosis can make people not react to pain because hypnosis separates the part of consciousness that registers pain from the part of consciousness that communicates with the outside world.
  • Many other researchers, such as Theodore Barber and Nicholas Spanos, think hypnosis happens when a suggestible person plays the role of a hypnotized person. According to this theory, hypnotized people simply behave as they think they are expected to.


Meditation is the practice of focusing attention. People meditate to enhance awareness and gain more control of physical and mental processes. Techniques used in meditation vary and include activities such as repetitive chanting and breathing exercises.

Meditative states are associated with an increase in alpha and theta brain waves, and physical indicators of relaxation such as slowed pulse and breathing. Some researchers have found that meditation has long-term effects such as improving physical and mental health and reducing stress. However, researchers disagree about whether meditative states are unique states of consciousness. Some researchers believe relaxation techniques can produce the same kind of state produced by meditation.

Psychoactive Drugs

Psychoactive drugs, as opposed to medicinal drugs, have psychological effects, meaning that they change sensory experience, perception, mood, thinking, and behavior. Psychoactive drugs are sometimes called recreational drugs, though some have legitimate medical uses.

Types of Recreational Drugs

Researchers usually classify recreational drugs into four types: stimulants, sedatives, narcotics, and hallucinogens.

  • Stimulants: drugs that stimulate the central nervous system
  • Sedatives: drugs that slow down the central nervous system
  • Narcotics: also called opiates; drugs that can relieve pain
  • Hallucinogens: drugs that cause sensory and perceptual distortions

Drugs derived from the cannabis plant, such as marijuana and hashish, have features of more than one of these drug types, so researchers sometimes consider cannabis to be a separate, fifth drug type.

Drug type Examples Effects Negative effects
Stimulants Nicotine, caffeine, cocaine, amphetamines, crystal meth Increased alertness and energy, excitation, euphoria, confidence Anxiety, restlessness, irritability, sleeplessness, paranoia, increased aggressiveness, feelings of panic
Sedatives Alcohol, Valium, Xanax, barbiturates, such as Seconal Euphoria, relaxation, less anxiety Impaired coordination, depression, lethargy, drowsiness, mood swings
Narcotics Morphine, heroin, opium, codeine, hydrocodone, such as Vicodin Euphoria, relaxation, less anxiety, less sensitivity to pain Lethargy, drowsiness, nausea, impaired coordinated, constipation
Hallucinogens LSD, mescaline, psilocybin Euphoria, changed perception, hallucinations, insightful moments Nausea, paranoia, anxiety, feelings of panic, mood swings, impaired judgment, jumbled thoughts
Cannabis Marijuana, hashish Euphoria, relaxation, increased awareness, changed perception Sluggishness, anxiety, impaired memory

How Psychoactive Drugs Work

Psychoactive drugs work by affecting neurotransmitter function. A single drug can affect the function of more than one neurotransmitter. Drugs can:

  • Cause more or less of a neurotransmitter to be released at synapses
  • Block reuptake of a neurotransmitter by presynaptic cells
  • Stimulate or block neurotransmitter receptors on postsynaptic cells
Influences on Psychoactive Drug Effects

A given drug doesn’t always have the same effect. If ten people drink beer one evening, they all may have different experiences. The effect of a drug depends on many different factors:

  • The amount of the drug
  • The potency of the drug
  • How the drug is administered
  • How much previous experience a user has with the drug
  • The user’s age and body weight
  • The user’s mood, personality, and motivation
  • The environment in which the drug is used
  • The user’s expectations about the drug’s effects
Chronic Use of Psychoactive Drugs

When people regularly use a drug, they may develop a tolerance to it. As time goes on, people with a tolerance need more and more of the drug to get the same effect.

When people stop using a drug after a long period of regular use, they often experience withdrawal symptoms. Different drugs produce different kinds of withdrawal symptoms. Not all drugs are addictive.

With chronic use, people can get physically or psychologically dependent on a drug. Physical dependence happens when a person must take the drug to avoid withdrawal symptoms. Psychological dependence is when a person keeps taking the drug because of cravings. A drug can be both physically and psychologically addictive.

Drug use can be dangerous for several reasons. Heavy or frequent use of drugs can damage body tissues and organs. Overdoses of some drugs, including sedatives, stimulants, and narcotics, can be lethal. Drugs can have dangerous indirect effects by causing people to behave in risky, accident-prone, or unhealthy ways.

More Help

Previous Next

Follow Us