-
Nearly 1 in 100 people will develop schizophrenia, joining the estimated 24 million across the world
-
schizophrenia
“split mind.” It refers not to a multiple-personality split but rather to a split from reality that shows itself in disorganized thinking, disturbed perceptions, and inappropriate emotions and actions.
-
psychotic disorder:
a psychological disorder in which a person loses contact with reality, experiencing irrational ideas and distorted perceptions. (p. 480)
-
delusions:
false beliefs, often of persecution or grandeur, that may accompany psychotic disorders. (p. 480)
-
A person with schizophrenia may have hallucinations (sensory experiences without sensory stimulation), seeing, feeling, tasting, or smelling things that are not there
Most often, however, hallucinations are auditory, frequently voices making insulting remarks or giving orders. The voices may tell the patient that she is bad or that she must burn herself with a cigarette lighter
-
emotions of schizophrenia are often utterly inappropriate, split off from reality
Some perform senseless, compulsive acts, such as continually rocking or rubbing an arm. Others, who exhibit catatonia, may remain motionless for hours and then become agitated.
-
Schizophrenia typically strikes as young people are maturing into adulthood
- men tend to be struck earlier, more severely, and slightly more often
- those who were not breast-fed, are more vulnerable
-
Schizophrenia patients with positive symptoms
experience hallucinations, talk in disorganized and deluded ways, and exhibit inappropriate laughter, tears, or rage
-
negative symptoms
toneless voices, expressionless faces, or mute and rigid bodies. Thus, positive symptoms are the presence of inappropriate behaviors, and negative symptoms are the absence of appropriate behaviors.
-
schizophrenia
For some, schizophrenia will appear suddenly, seemingly as a reaction to stress. For others, as was the case with Maxine, schizophrenia develops gradually
-
One rule holds true around the world
When schizophrenia is a slow-developing process (called chronic, or process, schizophrenia), recovery is doubtful
-
Those with chronic schizophrenia often exhibit the persistent and incapacitating negative symptom of social withdrawal
Men, whose schizophrenia develops on average four years earlier than women’s, more often exhibit negative symptoms and chronic schizophrenia
-
recovery
When previously well-adjusted people develop schizophrenia rapidly (called acute, or reactive, schizophrenia) following particular life stresses, recovery is much more likely. They more often have the positive symptoms that are more likely to respond to drug therapy
-
Schyzophrenia is a cluster of disorders
- Paranoid: halluncinations and delusions often of persecution
- Disorganized: speech and thought and behavior
- Catatonic: immobility or exess (-) or repeating otheres words and behaviors
- Undeferentiated: may varied symptoms
- Residual: withdrawl after delusions and hillucinations have dissapeard
-
DOPAMINE OVERACTIVITY
excess of receptors for dopamine linked to schyzophrenia
-
ABNORMAL BRAIN ACTIVITY AND ANATOMY
- Some have abnormally low activity in the frontal lobes, which are critical for reasoning, planning, and problem solving
- People diagnosed with schizophrenia also display a noticeable decline in the brain waves that reflect synchronized neural firing in the frontal lobes
-
PET scans of brain activity while people were hallucinating
their brain became vigorously active in several core regions, including the thalamus, a structure deep in the brain that filters incoming sensory signals and transmits them to the cortex
-
Another PET scan study of people with paranoia
found increased activity in the amygdala, a fear-processing center
-
findings
- Many studies have found enlarged, fluid-filled areas and a corresponding shrinkage of cerebral tissue in people with schizophrenia
- The greater the shrinkage, the more severe the thought disorder (
-
more findings
One smaller-than-normal area is the cortex. Another is the thalamus, which may explain why people with schizophrenia have difficulty filtering sensory input and focusing attention
-
Causes of schyzo
- are low birth weight and oxygen deprivation during delivery
- Famine may also increase risks
-
Genetic Factors
- These converging lines of evidence suggest that fetal-virus infections play a contributing role in the development of schizophrenia. They also strengthen the recommendation that “women who will be more than three months pregnant during the flu season” have a flu shot
- 2 percent of women who catch the flu during their second trimester of pregnancy bear children who develop schizophrenia
-
Genetic Factors
- The nearly 1-in-100 odds of any person’s being diagnosed with schizophrenia become about 1 in 10 among those whose sibling or parent has the disorder, and close to 1 in 2 if the affected sibling is an identical twin
- And, although only a dozen or so such cases are on record, the co-twin of an identical twin with schizophrenia retains that 1-in-2 chance when the twins are reared apart
-
genes cont...
- Nevertheless, the fact remains: Some identical twins, despite their shared genes, do not share a schizophrenia diagnosis. This difference tells us that genes are not the whole story.
- Twins who share a placenta are more likely to experience the same prenatal viruses. So it is possible that shared germs as well as shared genes produce identical twin similarities.
-
genes cont...
Twins who share a placenta are more likely to experience the same prenatal viruses. So it is possible that shared germs as well as shared genes produce identical twin similarities.
-
schizophrenia
is surely influenced by multiple genes with small effects, but identifying these genes has proven difficult
-
Summary
other factors—such as the prenatal viral infections, nutritional deprivation, andoxygen deprivation at birth mentioned earlier—may somehow help to “turnon” the genes that predispose some of us to this disease. As we have so often seen, nature and nurture interact. Neither hand claps alone.
|
|