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Medically reviewed on Jul 30, 2017 by L. Anderson, PharmD

What is Schizophrenia?

Schizophrenia is one of the most disabling medical conditions, and according to the World Health Organization (WHO), is considered a top ten illness contributing to the global burden of disease.

Individuals who have schizophrenia find it difficult to tell the difference between real and unreal experiences, to think logically, to have normal emotional responses to others, and to behave normally in social situations. Hallucinations, delusions, and extremely disordered thinking and speech, and inappropriate behavior can hinder daily functioning and the ability to work. Despite the perception of the general population, someone with schizophrenia is usually nonviolent and poses no threat to the safety of others.

Schizophrenia is thought to affect around 1% of the population worldwide, and approximately 2.4 million American adults (about 1.1 percent of the population age 18 and older) are affected by schizophrenia in a given year. It is a chronic, lifelong disease that requires ongoing treatment.

What Causes Schizophrenia?

Schizophrenia is a complex and puzzling illness, and even the experts in the field are not exactly sure what causes it. Some doctors think that the brain may not be able to process information correctly. A combination of genetics, environment, and altered chemistry may contribute to its development.

  • Genetics: Genetic factors appear to play a role as people who have family members with schizophrenia may be more likely to get the disease themselves.
  • Environment: Some researchers also believe that events in a person's environment can trigger schizophrenia. For example, problems during intrauterine development (infection) and birth may increase the risk for developing schizophrenia later in life.
  • Chemistry: Hormonal changes, or alterations in brain neurotransmitters like dopamine or glutamate may be involved.

Psychological and social factors may also play some role in its development. However, the level of social and familial support appears to influence the course of illness and may be protective against relapse.

Who is at Risk for Schizophrenia?

Schizophrenia appears to occur in slightly higher rates among men than in women (ration of 1.4 to 1, respectively), but women have a later onset. Schizophrenia often first appears in men in their late teens or early twenties; for women onset is usually in their late twenties or early thirties. Males therefore tend to account for more than half of patients in services; there is a high proportion of young adults. However, cases of late onset of the disorder (in individuals aged over 45 years) are known.

Childhood-onset schizophrenia can also begin after the age of 5 and, in most cases, after relatively normal development; but childhood schizophrenia is rare and can be difficult to differentiate from other pervasive developmental disorders of childhood, such as autism.

Symptoms of Schizophrenia

People with schizophrenia may show a variety of symptoms, but ultimately it is a thought disorder. Usually the illness develops slowly over months or even years. At first, the symptoms may not be noticed. For example, people may feel tense, may have trouble sleeping, or have trouble concentrating. They become isolated and withdrawn and they do not make or keep friends. As the illness progresses, psychotic symptoms develop.

Positive Symptoms: represents an exaggeration of normal processes.

  • Delusions - false beliefs or thoughts with no basis in reality. An example might be thinking that impending harm or death may occur, that one is famous or loved by a celebrity, or beliefs that aliens are inhabiting one's house.
  • Hallucinations - hearing (auditory), seeing (visual), feeling (somatic), smelling (olfactory), or tasting (gustatory) things that are not there. Hearing is the most common form of hallucination, occurring in 40 to 80 percent of people.
  • Disordered thinking and speech - thoughts "jump" between completely unrelated topics. The person may talk nonsense or answer questions with seemingly unrelated words.
  • Disordered motor behavior - bizarre motor behavior marked by a decrease in reactivity to the environment or hyperactivity that is unrelated to a stimulus. Their appearance or mood may show no emotion. Behavior can be childlike or agitated.

Negative Symptoms: lacking or a decreased presence of normal processes.

  • Examples of negative symptoms include a flat affect, decreased facial expressions, apathy, a monotone voice, and a lack of energy.
  • Negative symptoms can be primary or secondary. Secondary symptoms can be caused by antipsychotic medications.

Symptoms common in schizophrenia are shown below.

Catatonic symptoms:

  • Motor disturbances
  • Stupor
  • Negativism
  • Rigidity
  • Agitation
  • Inability to take care of personal needs
  • Decreased sensitivity to painful stimulus

Paranoid symptoms:

  • Delusional thoughts of persecution or of a grandiose nature
  • Anxiety
  • Anger
  • Violence
  • Argumentativeness

Disorganized symptoms:

  • Incoherence (not understandable)
  • Regressive behavior
  • Flat affect
  • Delusions
  • Hallucinations
  • Inappropriate laughter
  • Repetitive mannerisms
  • Social withdrawal


  • Patient may have symptoms of more than one subtype of schizophrenia.


  • Prominent symptoms of the illness have abated, but some features - such as hallucinations and flat affect - may remain.

No single characteristic is present in all types of schizophrenia.


The diagnosis of schizophrenia involves the presence of at least two of the five symptoms below and present for a minimum of a one-month period. Delusions, hallucinations or disorganized speech must be one of the symptoms:

  • Delusions
  • Hallucinations
  • Disorganized speech
  • Highly disorganized motor behavior
  • Negative symptoms such as flat affect

Call your doctor if:

  • Voices are telling you to hurt yourself
  • You are unable to care for yourself
  • You are feeling hopeless and overwhelmed
  • You feel like you cannot leave the house
  • You are seeing things that aren't really there

Treatment Options

During an acute episode of schizophrenia, hospitalization is often required to promote safety, and to provide for the person's basic needs such as food, rest, and hygiene.

Antipsychotic or neuroleptic medications work by changing the balances of chemicals in the brain and are used to control the symptoms of the illness. These medications are effective but they are also associated with side effects that may discourage a patient from taking them regularly. However, many of these side effects can be addressed and they should not prevent people from seeking treatment for this serious condition.

Atypical Antipsychotics

Generic Name Brand Name(s)
aripiprazole Abilify, , Abilify DiscmeltAbilify Maintena, Aristada
brexpiprazole Rexulti
cariprazine Vraylar
clozapine Clozaril, Fazaclo
iloperidone Fanapt
lurasidone Latuda
olanzapine Zyprexa, Zyprexa Zydis
paliperidone Invega
pimavanserin Nuplazid
quetiapine Seroquel, Seroquel XR
risperidone Risperdal, Risperdal M-Tab
ziprasidone Geodon

Typical Antipsychotics

Generic Name Brand Name(s)
chlorpromazine Thorazine (brand discontinued in US)
fluphenazine Prolixin (brand discontinued in US)
haloperidol Haldol (brand discontinued in US)
loxapine Loxitane (brand discontinued in US)
mesoridazine (generic discontinued in US) Serentil (brand discontinued in US)
molindone Moban (brand discontinued in US)
perphenazine Trilafon (brand discontinued in US)
prochlorperazine Compro Suppositories
thioridazine Mellaril (brand discontinued in US)
thiothixene Navane
trifluoperazine Stelazine (brand discontinued in US)

Common side effects from traditional antipsychotics may include:

  • Sedation
  • Weight gain
  • Extrapyramidal symptoms (muscle contractions, problems of movement and gait, and feelings of restlessness or "jitters")
  • Long-term risks include a movement disorder called tardive dyskinesia, which involves involuntary movements.

Newer agents known as atypical antipsychotics have a somewhat better safety profile regarding side effects. Ongoing treatment with medications is usually necessary to prevent a return of symptoms.

Supportive and problem-focused forms of psychotherapy may be helpful for many individuals. Behavioral techniques, such as social skills training, can be used in a therapeutic setting or in the patient's natural environment to promote social and occupational functioning.

Family interventions that combine support and education about schizophrenia (psychoeducation) appear to help families cope and reduce relapse. Patients who lack family and social support may be helped by intensive case management programs that emphasize active outreach and linkage to a range of community support services.

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