What are antipsychotic drugs?

Antipsychotic medications are prescription drugs used in the treatment of mental illnesses characterized by psychosis, such as schizophrenia and bipolar disorder.

What is psychosis?

Psychosis is a severe mental condition in which a person loses the ability to recognize reality or relate to others.  The symptoms of psychosis usually includes paranoia, false ideas about what is taking place or who one is (delusions) and seeing or hearing things that aren't there (hallucinations).

What is schizophrenia?

Schizophrenia is a chronic, severe, and disabling mental illness.  People with schizophrenia sometimes hear voices others don’t hear, believe that others are broadcasting their thoughts to the world, or become convinced that others are plotting to harm them. These experiences can make them paranoid and withdrawn and cause difficulties when they try to have relationships with others.  People with schizophrenia may not make sense when they talk, may sit for hours without moving or talking much, or may seem perfectly fine until they talk about what they are really thinking.

What are the symptoms of schizophrenia?

The symptoms of schizophrenia fall into three broad categories:

  • Positive symptoms are unusual thoughts or perceptions, including hallucinations, delusions, thought disorder, and disorders of movement.
  • Negative symptoms represent a loss or a decrease in the ability to initiate plans, speak, express emotion, or find pleasure in everyday life. These symptoms are harder to recognize as part of the disorder and can be mistaken for laziness or depression.
  • Cognitive symptoms (or cognitive deficits) are problems with attention, certain types of memory, and the executive functions that allow us to plan and organize. Cognitive deficits can also be difficult to recognize as part of the disorder but are the most disabling in terms of leading a normal life.

Positive symptoms

Positive symptoms are easy-to-spot behaviors not seen in healthy people and usually involve a loss of contact with reality. They include hallucinations, delusions, thought disorder, and disorders of movement. Positive symptoms can come and go. Sometimes they are severe and at other times hardly noticeable, depending on whether the individual is receiving treatment.

Hallucinations.  A hallucination is something a person sees, hears, smells, or feels that no one else can see, hear, smell, or feel. "Voices" are the most common type of hallucination in schizophrenia. Many people with the disorder hear voices that may comment on their behavior, order them to do things, warn them of impending danger, or talk to each other (usually about the patient). They may hear these voices for a long time before family and friends notice that something is wrong. Other types of hallucinations include seeing people or objects that are not there, smelling odors that no one else detects (although this can also be a symptom of certain brain tumors), and feeling things like invisible fingers touching their bodies when no one is near.

Delusions.  Delusions are false personal beliefs that are not part of the person's culture and do not change, even when other people present proof that the beliefs are not true or logical. People with schizophrenia can have delusions that are quite bizarre, such as believing that neighbors can control their behavior with magnetic waves, people on television are directing special messages to them, or radio stations are broadcasting their thoughts aloud to others. They may also have delusions of grandeur and think they are famous historical figures. People with paranoid schizophrenia can believe that others are deliberately cheating, harassing, poisoning, spying upon, or plotting against them or the people they care about. These beliefs are called delusions of persecution.

Thought Disorder.  People with schizophrenia often have unusual thought processes. One dramatic form is disorganized thinking, in which the person has difficulty organizing his or her thoughts or connecting them logically. Speech may be garbled or hard to understand. Another form is "thought blocking," in which the person stops abruptly in the middle of a thought. When asked why, the person may say that it felt as if the thought had been taken out of his or her head. Finally, the individual might make up unintelligible words, or "neologisms."

Disorders of Movement.  People with schizophrenia can be clumsy and uncoordinated. They may also exhibit involuntary movements and may grimace or exhibit unusual mannerisms. They may repeat certain motions over and over or, in extreme cases, may become catatonic. Catatonia is a state of immobility and unresponsiveness. It was more common when treatment for schizophrenia was not available; fortunately, it is now rare.2

Negative symptoms

The term "negative symptoms" refers to reductions in normal emotional and behavioral states. These include the following:

  • flat affect (immobile facial expression, monotonous voice),
  • lack of pleasure in everyday life,
  • diminished ability to initiate and sustain planned activity, and
  • speaking infrequently, even when forced to interact.

People with schizophrenia often neglect basic hygiene and need help with everyday activities. Because it is not as obvious that negative symptoms are part of a psychiatric illness, people with schizophrenia are often perceived as lazy and unwilling to better their lives.

Cognitive symptoms

Cognitive symptoms are subtle and are often detected only when neuropsychological tests are performed. They include the following:

  • poor "executive functioning" (the ability to absorb and interpret information and make decisions based on that information),
  • inability to sustain attention, and
  • problems with "working memory" (the ability to keep recently learned information in mind and use it right away)

Cognitive impairments often interfere with the patient's ability to lead a normal life and earn a living. They can cause great emotional distress.

How do antipsychotic drugs work?

Antipsychotic drugs, also known as neuroleptics, work by blocking the absorption of the neurotransmitter, dopamine.  Dopamine is 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.  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.

What types of antipsychotic medications are there?

There are two main types of antipsychotic drugs.  There is the older “typical” antipsychotics (also known as “first generation” antipsychotics) and the newer “atypical” antipsychotics (also known as “second generation” antipsychotics.   The newer “atypical” antipsychotics more selectively block dopamine D2 receptors in the brain and have little or no affinity for dopamine D1 receptors.  It is the blockage of D1 receptors that is believed to be the cause of the higher incidence of side effects seen with first generation antipsychotics.

First-generation or typical antipsychotic drugs include haloperidol, chlorpromazine and fluphenazine.

Typical antipsychotics are also some times called conventional antipsychotics, classical neuroleptics, or major tranquilizers.

Second-generation or atypical antipsychotic drugs include Abilify, Clozaril, Zyprexa, Seroquel, Risperdal and Geodon

What are the side effects of antipsychotic drugs?

The specific side effects caused by an antipsychotic medicine, and the severity of those side effects, depends not only on the particular type of antipsychotic (typical or atypical) but also on the specific drug being taken.  For a more complete list of side effects please click on a particular drug from the list above and review the drug information provided for that specific drug.

Some common side effects of antipsychotic drugs include sedation, movement disorders, heart problems, weight gain, and diabetes.

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