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Schizophrenia Fact Sheet
Schizophrenia, the most chronic and disabling of the severe mental disorders,
is a major focus of research at the National Institute of Mental Health (NIMH),
the world's foremost mental health scientific organization. This Federal agency
takes the lead in neuroscientific investigation devoted to understanding the
causes, diagnosis, prevention, and treatment of schizophrenia and other mental
disorders, which afflict millions of Americans.
Since the Institute's inception 50 years ago, much has been learned about mental
disorders and their effects on the brain. Revolutionary scientific advances
in neuroscience, molecular biology, genetics, and brain imaging have provided
some of the greatest insights into the complex organ that is the seat of thought,
memory, and emotion. Thanks to these new tools, the scientific evidence that
mental illnesses are brain disorders now exists.
More than 2 million Americans are affected by schizophrenia in any given year,
and only one in five recovers completely. The illness, which may impair a person's
ability to manage emotions, interact with others, and think clearly, typically
develops in the late teens or early twenties. Symptoms include hallucinations,
delusions, disordered thinking, and social withdrawal. Most people with schizophrenia
continue to suffer chronically or episodically throughout their lives. Even
between bouts of active illness, lost opportunities for careers and relationships,
stigma, residual symptoms, and medication side effects often plague those with
the illness. One of every 10 people with schizophrenia eventually commits suicide.
According to 1990 data, the most recent available, schizophrenia costs the
nation $32.5 billion annually.
During the last decade, NIMH research has led to dramatic advances
in the treatment of schizophrenia -- primarily in the development of several
new medications with fewer side effects. However, some symptoms, such as social
withdrawal and loss of motivation, are still insufficiently treated by the
new drugs. Studies are continuing to determine how these and other promising
medications interact with specific neurotransmitter systems in the brain and
to ascertain which drugs work best for which people. In addition, a large-scale community study has shown that less than half of patients with schizophrenia
receive appropriate treatment -- medication doses may have been incorrect and
there was often inadequate use of psychosocial, vocational, and family therapies.
As the search for better treatments and ways to transfer those
treatments to clinical practice continues, NIMH is harnessing the most sophisticated
scientific tools available to determine the causes of schizophrenia. This
brain disorder, like heart disease or diabetes, is complex and likely results
from the interplay of genetic, behavioral, developmental, and other factors.
There is an active search on several levels for the specific risk factors
that may lead to schizophrenia.
Many years of family studies indicate that a vulnerability to
schizophrenia is inherited. Still, scientists do not know how many genes are
involved in this complex disorder, how the genetic predisposition is transmitted,
or how behaviors or other events may interact with a genetic vulnerability
to trigger the disorder. But an arsenal of new molecular tools and modern
statistical analyses are allowing researchers to close in on particular genes
that might make people more susceptible to schizophrenia by affecting, for
example, brain development or neurotransmitter systems governing brain functioning.
On another research front, investigators supported by NIMH are
using state-of-the-art imaging techniques to study the living brain. They
have recently discovered specific, subtle abnormalities in the structure and
function of the brains of patients with schizophrenia that may provide new
insights into the origins of the disease. In other imaging studies, scientists
have found evidence of early biochemical changes that may precede the onset
of disease symptoms, prompting examination of the neural circuits that are
most likely to be involved in producing those symptoms.
Research evidence from developmental neurobiologists suggests
that schizophrenia may result when neurons form inappropriate connections
during fetal development.
Thanks to NIMH research, a number of new antipsychotic
drugs, "atypical antipsychotics," have been introduced since 1990. The
first, clozapine (Clozaril(r)), is more effective than older antipsychotics,
although it has possible severe side effects, such as agranulocytosis-- a loss of white blood cells that fight infection -- that require patients
to be frequently monitored with blood tests. The newer atypical medications,
such as risperidone (Risperdal(r)), quetiapine (Seroquel(r)), and olanzapine
(Zyprexa(r)), are safer than the older drugs or clozapine and have fewer
side effects, so they may be better tolerated by patients. NIMH is supporting
clinical trials to further understand the role of atypical antipsychotics
in treating schizophrenia.
Although a defect may be present at birth, it may lie dormant
until puberty, a time when significant nerve cell reorganization occurs in
the brain. This research has spurred efforts to identify prenatal factors,
including infections in utero, that may affect development.
National Institute of Mental Health
Office of Communications and Public Liaison
6001 Executive Boulevard, Rm. 8184, MSC 9663
Bethesda, MD 20892-9663
NIH Publication No. 99-4500
Updated: June 27, 2002