Psychiatry: Behavioral Sciences/Clinical
Psychiatry 11th Edition
Schizophrenia
Although schizophrenia is discussed as if it is a single disease, it probably comprises a
group of disorders with heterogeneous etiologies, and
it includes patients whose clinical presentations, treatment response, and courses of
illness vary. Signs and symptoms are variable and
include changes in perception, emotion, cognition, thinking, and behavior.
Diagnosis, Signs, and Symptoms
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Typical Age of Schizophrenic onset?
The disorder usually begins before age 25 years, persiststhroughout life, and affects
persons of all social classes.
The Four As of Schizophrenia
Autism, Affect, Associations, Ambivalence
Reproductive Factors
First-degree biological relatives of persons with schizophrenia
have a ten times greater risk for developing the disease than the general population.
Medical Illnesses: Schizophrenia
Several studies have shown that up to 80
percent of all schizophrenia patients have significant concurrent medical illnesses and
that up to 50 percent of these conditions may be undiagnosed.
,Infection and Birth Season
Season-specic risk factors, such as a virus or a seasonal change in diet, may be
operative. Another hypothesis is that persons
with a genetic predisposition for schizophrenia have a decreased biological advantage
to survive season-specific insults.
Nicotine
Up to 90 percent of schizophrenia patients may be dependent on nicotine. Apart from
smoking-associated mortality, nicotine
decreases the blood concentrations of some antipsychotics. There are suggestions that
the increased prevalence in smoking is due, at least in
part, to brain abnormalities in nicotinic receptors
Population Density
The effect of
population density is consistent with the observation that the incidence of schizophrenia
in children of either one or two parents with
schizophrenia is twice as high in cities as in rural communities. These observations
, suggest that social stressors in urban settings may aect
the development of schizophrenia in persons at risk.
Socioeconomic and Cultural Factors: Schizophrenia
Because schizophrenia begins early in life; causes significant and long-lasting
impairments; makes heavy demands for
hospital care; and requires ongoing clinical care, rehabilitation, and support services,
the financial cost of the illness in the United States is
estimated to exceed that of all cancers combined. Patients with a diagnosis of
schizophrenia are reported to account for 15 to 45 percent of
homeless Americans.
Hospitalization
The probability of readmission within 2 years after discharge from the first
hospitalization is about 40 to 60 percent. Patients with schizophrenia occupy about 50
percent of all mental hospital beds and account for
about 16 percent of all psychiatric patients who receive any treatment.
ETIOLOGY
Genetic Factors: Schizophrenia