Other Free Encyclopedias » Science Encyclopedia » Science & Philosophy: Anticolonialism in Southeast Asia - Categories And Features Of Anticolonialism to Ascorbic acid

Antipsychotic Drugs

mental person dopamine psychosis

An antipsychotic drug, sometimes called a neuroleptic, is a prescription medication used to treat psychosis. Psychosis is a major psychiatric disorder characterized by derangement or disorganization of personality and/or by the inability to tell what is real from what is not real, often with hallucinations, delusions, and thought disorders. People who are psychotic often have a difficult time communicating with or relating to others. Sometimes they become agitated and violent. They may hear voices, see things that aren't really there, and have strange or untrue thoughts, such as believing that other people can hear their thoughts or are trying to harm them. They may also neglect their appearances and may stop talking or talk only "nonsense."

Among the conditions considered to be psychoses are schizophrenia, major depression, and bipolar affective disorder (manic depression). Psychosis can arise from emotional or organic causes. Organic causes include brain tumors, drug interactions, and substance abuse. Antipsychotic drugs do not cure mental illness, but can reduce some of the symptoms or make them milder. The medicine may improve symptoms enough for the person to undergo counseling and live a more normal life. The type of antipsychotic medicine prescribed depends on the type of mental problem the patient has.

The vast majority of antipsychotics work by blocking the absorption of dopamine, a chemical that occurs naturally in the brain and is responsible for causing psychotic reactions, especially those that happen as a result of mental illness. Dopamine is one of the substances in the brain responsible for transmitting messages across the gaps, or synapses, of nerve cells. Too much dopamine in a person's brain speeds up nerve impulses to the point of causing hallucinations, delusions, and thought disorders. By blocking the dopamine receptors, antipsychotics reduce the severity of these symptoms. The brain has several types of dopamine receptors, and their unselective blockage by antipsychotic drugs causes the side effects.

When a patient takes an antipsychotic drug, he or she enters what is called a neuroleptic state. Impulsiveness and aggression decrease as do concern and arousal about events going on in the environment outside the person. The person taking the drug has fewer hallucinations and delusions as well. Once these symptoms are controlled by antipsychotic drugs, he or she can live a more normal life, and physicians can more easily treat the cause of the psychosis.

Antipsychotic medications were not used in the United States before 1956. The first drug used to treat psychosis was reserpine, which is made from a plant called rauwolfia. Reserpine was first made in India, where rauwolfia had been used to treat psychotic symptoms for centuries. Chlorpromazine, which was invented at about the same time and marketed under the name Thorazine, soon became the most favored drug. Once these and other antipsychotic medicines were introduced in the United States, they gained widespread acceptance for the treatment of schizophrenia. The use of these drugs allowed the release of many people who had been confined to mental institutions.

Antipsychotic drugs are also known as neuroleptics or major tranquilizers. Several types of these drugs are available, such as haloperidol (Haldol), lithium (Lithonate), chlorpromazine (Thorazine), and thioridazine (Mellaril). The newer antipsychotics include risperidone (Risperdal), quetiapine (Seroquel) and olanzapine (Zyprexa). These medicines are available only with a physician's prescription. The recommended dosage depends on the type of antipsychotic drug, the condition for which it is prescribed, and other factors. Despite their benefits, antipsychotic medicines have a number of strong side effects.

Although it usually takes at least two weeks for the drug to work on symptoms of psychosis, side effects often show up sooner. The most severe include muscle rigidity, muscle spasms, twitching, and constant movement. Tardive dyskinesia (TD)—a rhythmic, uncontrollable movement of the tongue, lips, jaw, or arms and legs—develops after a mental patient has taken an antipsychotic drug for a longer period of time. Twenty-six percent of chronically mentally ill people who are, or have been hospitalized develop TD. Often these side effects do not disappear when a person stops taking his or her medication.

Perhaps the most serious side effect of antipsychotic medications is neuroleptic malignant syndrome or NMS, a condition that occurs when someone taking an antipsychotic drug is ill or takes a combination of drugs. People with NMS cannot move or talk. They also have unstable blood pressure and heart rates. Often NMS is fatal. Even when the person recovers, he or she has an 80% chance of experiencing NMS again if given antipsychotic drugs.

Today a new generation of antipsychotics has been developed as a result of recent molecular biology discoveries about how the brain works. These new drugs have fewer side effects. Some do not completely block dopamine receptors; others are more selective, blocking only one type of dopamine receptor. A few of the newer drugs block serotonin or glutamate, two other neurotransmitters.



American Psychiatric Association. Let's Talk about Psychiatric Drugs. Washington, DC: American Psychiatric Association, 1993.

Buelow, George, and Suzanne Hebert. Counselor's Resource on Psychiatric Medications, Issues of Treatment and Referral. Pacific Grove, CA: Brooks/Cole, 1995.

Shives, Louise Rebecca. Basic Concepts of Psychiatric-Mental Health Nursing. 4th ed. Philadelphia: Lippincott Williams & Wilkins, 1997.

Kay Marie Porterfield


. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Bipolar affective disorder (manic depression)

—A mental illness characterized by severe mood swings from depression to mania (great enthusiasm, energy, and joy).


—Fixed, false beliefs that are resistant to reason or factual disproof.


—A sensory experience of something that does not exist outside the mind. A person can experience a hallucination in any of the five senses.


—A mental illness characterized by thought disorder, distancing from reality, and sometimes delusions and hallucinations.

[back] Antiparticle - Dirac's Hypothesis, Other Antiparticles, Antimatter, Antiparticles And Cosmology

User Comments

Your email address will be altered so spam harvesting bots can't read it easily.
Hide my email completely instead?

Cancel or

Vote down Vote up

almost 4 years ago

Antipsychotic Drugs

Vote down Vote up

about 4 years ago

I just want to say something about the coment in distancing oneself from others always have since childhood I new people not to be trusted always keeping away,now that I am sicker I still distance myself from others don't trust anyone...that I get from talking to my grandfather may he love his peace...I don't go to any regular doctor I personaly now them...my situation is not as bad as my sisters they don't care about doctors one is like me and the other is like mother...I can only tell them hope you now whats better for you and I leave...I now for a fact that these medicines I'm taking will affect me in the long run but I'm optomistic that I will ba fine...I have cared for myself the best way I can and hoping to see another day...this illness is the only one I cant fix,you people have what I need so that is why I go to the doctor in the first place.

Vote down Vote up

about 4 years ago

I am confused and hoping you can answer a question for me.

I have two relatives with mental disorders. One is a schizophreniac and doing well. The other, my younger sister, is in terrible shape. She just spent two weeks in the mental health section of a major hospital for a medication "adjustment" and nothing has changed. I spoke to her primary physician (my sister has gven documented permission to discuss her condition with this doctor.

I have read about "new" drugs for mental disorders, but the thing about the discussion with her doctor that stuck with me is that she said no drugs have been developed for many years that use new base chemistry (my words, not hers, I can't remember how she put it.) She explained this by saying the ingredients that actually fight the psychosis are the same ones developed in the 50's and seventies.

This is not encouraging. Can you tell me what the truth is?

Thank you.