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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) is affected by schizophrenia in a given year. Individuals who have the disorder 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.

What causes Schizophrenia and who is at risk?

Schizophrenia is a complex and puzzling illness. 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.

Genetic factors appear to play a role as people who have family members with schizophrenia may be more likely to get the disease themselves. 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.

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.

Schizophrenia appears to occur in equal rates among men and women, but women have a later onset. Schizophrenia often first appears in men in their late teens or early twenties but for women onset is usually in their 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.

Types of Schizophrenia

There are 5 recognized types of schizophrenia:

  • catatonic
  • paranoid
  • disorganized
  • undifferentiated, and
  • residual

Features of schizophrenia include its typical onset before the age of 45, the continuous presence of symptoms for 6 months or more, and deterioration from a prior level of social and occupational functioning.

Symptoms of Schizophrenia

People with schizophrenia may show a variety of symptoms. 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:

  • Delusions - false beliefs or thoughts with no basis in reality
  • Hallucinations - hearing, seeing, or feeling things that are not there
  • Disordered thinking - thoughts "jump" between completely unrelated topics (the person may talk nonsense)
  • Catatonic behavior - bizarre motor behavior marked by a decrease in reactivity to the environment or hyperactivity that is unrelated to a stimulus
  • Flat affect - an appearance or mood that shows no emotion

Symptoms common to each type of schizophrenia are shown below.

Catatonic type:

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

Paranoid type:

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

Disorganized type:

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

Undifferentiated type:

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

Residual type:

  • 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.


Psychiatrists usually make a final diagnosis of schizophrenia because other diseases can also cause symptoms of psychosis. Therefore, an individual who is suspected of having schizophrenia will undergo a thorough psychiatric interview; family members will also be interviews. However, there are, as yet, no medical tests that can give a definite diagnosis of schizophrenia. The following factors may suggest a schizophrenia diagnosis, but do not confirm it:

  • Developmental background
  • Genetic and family history
  • Changes from level of functioning prior to illness
  • Course of illness and duration of symptoms
  • Response to pharmacological therapy

CT scans of the head and other imaging techniques may identify some changes associated with schizophrenia in the research literature and may rule out other neurophysiological disorders.

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.

Typical Antipsychotics

Generic Name Brand Name(s)
chlorpromazine Thorazine
fluphenazine Prolixin
haloperidol Haldol
loxapine Loxitane
mesoridazine Serentil
perphenazine Trilafon
prochlorperazine Compazine, Compazine Spansule
thioridazine Mellaril
thiothixene Navane
trifluoperazine Stelazine

Atypical Antipsychotics

Generic Name Brand Name(s)
aripiprazole Abilify, , Abilify Discmelt
clozapine Clozaril, Fazaclo
olanzapine Zyprexa, Zyprexa Zydis
paliperidone Invega
quetiapine Seroquel
risperidone Risperdal, Risperdal M-Tab
ziprasidone Geodon

Common side effects from traditional antipsychotics may include sedation and weight gain. Other side effects are known as 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 appear to have a somewhat better safety profile regarding side effects. They also appear to help people who have not benefited from the older traditional medications. 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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