Their teeth looked like fangs
ready to devour me. Most of the time I couldn't trust myself to look at
anyone for fear of being swallowed. I had no respite from the illness.
Even when I tried to sleep, the demons would keep me awake. . . .
Schizophrenia is the most serious of the mental illnesses
- affecting roughly one percent of the population worldwide - and it is,
perhaps, the most feared. There are a number of excellent introductions
to the topic. For example, you can visit the Web page Schizophrenia
from the National Institute of Mental
Health.
Many
factors, from genes to fetal environment, trigger this disease.
Because many loci have been associated with this disease,
multiple genetic "hits" appear necessary to result in a predisposition
to schizophrenia. Although no single gene confers susceptibility, genes
are clearly involved. People with a first-order relative with the disease
face a much higher risk - as high as 50 percent for monozygotic twins -
than the general population. The genetic risk is reviewed in the Schizophrenia
section of Genetics
and Mental Disorders. Prenatal risk factors include: maternal obesity
prior to pregnancy, influenza during second trimester, and obstetrical
complications resulting in hypoxia. Citations for recent research on these
topics can be found at Prenatal
Problems Linked to Schizophrenia.
Like other mental illnesses, schizophrenia's symptoms
reflect an underlying brain disorder. The anatomy and chemistry of the
brains of schizophrenics differ markedly both from healthy individuals
and from those with other psychiatric disorders. For instance, the brains
of schizophrenics are smaller and have abnormal dopamine function, increased
ventricular size, unusual laterality of the cortex, and more subtle differences.
The
brain glitch arises early in development.
Just what causes this neural pathology is unknown, as is
how altered brain structure translates into schizophrenic symptoms. Recently,
a new vision of schizophrenia and its etiology came up, one that considers
schizophrenia as a unitary, if not strictly localized, entity. In Dana.org's
Brain Work, Nancy
Andreasen wrote, "These newer models localize the symptoms of schizophrenia
in distributed circuits, not in single regions. A disruption at the level
of circuits may lead to an impairment in basic cognitive processes, such
as good mental coordination of ideas or the ability to use abstract concepts
to guide behavior." These basic disturbances then result in symptoms, which
may vary between individuals depending on what part of the circuit is most
severely disrupted. The disordered circuit is thought to include the prefrontal
cortex, the thalamus, elements of the limbic system, and perhaps the cerebellum.
Recent theories do concur in that they are all developmental
models that locate the primary lesion to the brain very early in development.
The underlying neural pathology is thought to remain relatively dormant
until the final maturation of the brain, which occurs during adolescence.
For a thorough review of this, see The
Neurodevelopmental Hypothesis of Schizophrenia. Much evidence supports
this hypothesis. The brains of schizophrenics exhibit unusual folding of
the cortex, a process that occurs in utero. Large residues of subplate
cells, which normally disappear during development, are found in the brains
of some schizophrenics. These cells help guide migrating neurons to their
destinations, so their continued presence in adults suggests a mechanism
for how the brains of schizophrenics become "mis-wired."
Related
symptoms appear in childhood.
The existence of prenatal/perinatal risk factors also supports
developmental models. A number of prospective studies revealed that those
who become schizophrenic appear different early in life. As children, they
experience speech problems, deficiencies in perceptual and motor skills,
preference for solitary play, social anxiety, and slightly lower IQs, indicating
that neurological differences exist long before the disease becomes manifest.
Indeed, magnetic resonance imaging of the brains in people at high risk
of developing schizophrenia suggests that abnormalities in brain structure
precede the appearance of symptoms.
The acceptance of schizophrenia as a brain-based biological
disorder, one that alters consciousness, is quite a change from 50 years
ago, when researchers thought children were driven mad by their "schizophrenogenic"
mothers. Now, we see schizophrenia as analogous to cancer in many ways
- as a complex disease with many interacting etiological factors, one that
requires the occurrence of many unfortunate events. With this understanding
comes hope for better treatments and for effective intervention in the
earliest parts of the disease process.
Cindy
Seiwert is a freelance science writer based in Haddam, Connecticut.
Frederick
H. Carlson is a professional artist and illustrator whose clients include
The Saturday Evening Post, Baltimore Sun and
Pittsburgh Magazine.
Endlinks
What Is Schizophrenia?
- home page of the Schizophrenia Society of Canada. Includes links to news,
a discussion forum, and regional groups.
APA Online - home
page of the American Psychiatric Association. Supplies news, clinical and
research resources, a job bank, and public policy statements.
Schizophrenia
- a broad collection of links. Provides information on diagnosis, treatment,
and clinical trials, plus links to professional and advocacy organizations.
Schizophrenia
- general information from the National Institute of Mental Health. Includes
press releases, editorials, congressional testimony, and various publications.
Schizophrenia
- links to current clinical trials relevant to this disease.
Schizophrenia
Research Topics - a comprehensive site for searching the scientific
research on schizophrenia, from Internet Mental Health. Covers subjects
from behavioral therapy to virology.
