Schizophrenia
What is Schizophrenia?
• Ability to function is impaired by severely
distorted beliefs, perceptions, and thought
processes
• Comes from Greek meaning “split” and “mind”
– ‘split’ refers to loss of touch with reality
– not dissociative state
– not ‘split personality’
• Equally split between genders, males have
earlier onset
– 18 to 25 for men
– 26 to 45 for women
Symptoms of Schizophrenia
• Positive symptoms
– Excess of or distortion of normal functions
• Hallucinations – false perceptions (auditory or visual)
• Delusions – false beliefs
• Negative symptoms
– absence of normal cognition or affect
• flat affect – emotionally “flat”
• alogia - poverty of speech
• avolition – inability to do simple goal-directed behaviors
(dressing, bathing, social activities)
• Disorganized Symptoms
– Disorganized Speech or Behavior
Disorganized Speech
• Word Salad - a string of words that vaguely resembles
language, and may or may not be grammatically correct,
but is utterly meaningless.
– “Tramway flogging into my question, are you why is it
thirty letters down under peanut butter, what is it.”
• Neologisms - Making up words
– “I am going to the park to ride the wallywhoop.”
• Clang Speech - Rhyming all the words .
– “Deck the halls with boughs of holly, folly, polly,
dolly, hello Dolly, want a lollipop?”
• Echolalia - Repeating exactly what someone else has said
• Echopraxia - Repeating exactly what someone else has
done.
Disorganized Behavior
• Perseveration - Repeating the same activity
(word or behavior) over and over again.
• Dressing oddly, such as wearing many sets
of clothing one over the other or wearing
hats, gloves, and heavy coats in the summer.
• Doing things in public that are usually done
only in private. For example: urinating on a
street corner.
Common Delusions
• Delusions of reference - believes that other people
are constantly talking about her or that everything that
happens is somehow related to her
• Delusions of persecution - believes that others are
plotting against or trying to harm him or someone
close to him
– ‘they’re out to get me’
– paranoia
• Delusions of grandeur - believes he is extremely
important, powerful, or wealthy.
– “God” complex
– megalomania
• Delusions of being controlled
– the CIA is controlling my brain with a radio signal
Symptoms of Schizophrenia
• Hallucinations
– hearing or seeing things that aren’t there (most common are
auditory)
– contributes to delusions
– command hallucinations: voices giving orders
• Disorganized speech
– Over-inclusion—jumping from idea to idea without the
benefit of logical association
– Paralogic—on the surface, seems logical, but seriously
flawed
• e.g., Jesus was a man with a beard, I am a man with a beard,
therefore I am Jesus
• Disturbances in sensation
– sights, sounds, and other sensations feel distorted
Symptoms of Schizophrenia
• Disorganized behavior and affect
– behavior is inappropriate for the situation
• e.g., wearing sweaters and overcoats on hot days
– affect is inappropriately expressed
• flat affect—no emotion at all in face or speech
• inappropriate affect—laughing at very serious things,
crying at funny things
– catatonic behavior
• unresponsiveness to environment, usually marked by
immobility for extended periods
Frequency of positive and negative symptoms in individuals at the time they were
hospitalized for schizophrenia. Source: Based on data reported in Andreasen &
Flaum, 1991.
Schizophrenia: An Example
• Watch Module 26 from The Brain dvd (5
min).
• As you watch Jerry write down what
symptoms you see him demonstrating.
Subtypes of Schizophrenia
• Paranoid type
– delusions of persecution
• believes others are spying and plotting
– delusions of grandeur
• believes others are jealous, inferior, subservient
– no cognitive impairment, disorganized behavior, or
negative symptoms
• Catatonic type—unresponsive to surroundings,
purposeless movement, parrot-like speech
– waxy flexibility
– highly disturbed movements or actions
Types of Schizophrenia
• Disorganized type
– delusions and hallucinations with little meaning
– disorganized speech, behavior, and flat affect
• Undifferentiated type – exhibits
symptoms of schizophrenia but can’t be fit
into one of the 3 subtypes.
Prevalence of Schizophrenia
• Onset of schizophrenia typically occurs
during young adulthood.
• Approximately 1 million Americans are
treated for schizophrenia annually
• Worldwide, about 1% of the population
will experience at least one episode of
schizophrenia at some point in life
Course of Schizophrenia:
The ¼, ¼, ½ Rule
• Enormous individual variability
• About 1/4 of those who experience an
episode of schizophrenia recover completely;
another 1/4 experience recurrent episodes,
but often with only minimal impairment of
functioning
• The other one-half, schizophrenia becomes a
chronic mental illness, and the ability to
function normally in society may be severely
impaired.
Schizophrenia and Genetics
Risk increases with genetic similarity
50
40
40
Lifetime risk
of developing
schizophrenia
for relatives of
a schizophrenic
30
30
20
10
10
0
0
Fraternal Children
Identical
of two
twin
General
Siblings
twin
Children
schizophrenia
population
victims
CAUSES OF THE DISEASE
• BIOLOGICAL
- GENETIC FACTORS
- PRE-NATAL FACTORS
- STRUCTURAL FACTORS
-DOPAMINE THEORY
-INFECTIONS
• SOCIAL
- LIFE EXPERIENCES
- EVOLUTIONARY HYPOTHESIS
• DIATHESIS-STRESS THEORY
– VULNERABILITY THEORY
Developing Schizophrenia
The lifetime risk of developing schizophrenia varies with one's genetic
relatedness to someone having this disorder. Across countries, barely
more than 1 in 10 fraternal twins, but some 5 in 10 identical twins, share
a schizophrenia diagnosis. (Adapted from Gottesman, 2001.)
The Heritability of Schizophrenia
The researchers looked for signs
of schizophrenia in the
biological and adoptive relatives
of people who had been adopted
at an early age and either did or
did not subsequently develop
schizophrenia. The results here
are the percentage of relatives
who showed either
schizophrenia or a milder
disorder now called schizotypal
personality disorder. (Data from
Kety & others, 1976.)
POSSIBLE
BIOLOGICAL
FACTORS
Paternal age: Older fathers
and the risk of schizophrenia
• Because schizophrenia often occurs in
individuals with no family history of mental
disorders, no genetic model explains all the
patterns of schizophrenia
• Researchers in Jerusalem reviewed data on
87,000 people and found that paternal age
was a strong and significant predictor of the
schizophrenia diagnosis. (Mother’s age
appeared to play no role.)
• Paternal age failed to account for threequarters of the cases of schizophrenia.
Biological Bases of
Schizophrenia
• Other congenital influences
– difficult birth (e.g., oxygen deprivation)
– prenatal viral infection
• Brain chemistry
– neurotransmitter excesses or deficits
– dopamine theory
The Dopamine Theory
• Theory: Schizophrenia is caused by excess
dopamine
• Drugs that reduce dopamine reduce symptoms
• Drugs that increase dopamine produce
symptoms even in people without the disorder
• Dopamine theory not enough; other
neurotransmitters involved as well
Other Biological Factors
• About half the people with schizophrenia
show some type of brain structure
abnormality
• Brain structure and function
– enlarged cerebral ventricles and reduced neural tissue
around the ventricles
– PET scans show reduced frontal lobe activity
• Early warning signs
– nothing very reliable has been found yet
– certain attention deficits can be found in children who are
at risk for the disorder
Brain Activity & Tissue Loss
• One five-year prospective study compared brain
structure changes in normal adolescents and
adolescents with early onset schizophrenia
• Gray matter tissue loss ranged from about 1 percent in
the normal teens to more than 5 percent in the
schizophrenic teens
• The amount of gray matter loss was directly correlated to
the teenage patient’s clinical symptoms
– More rapid gray matter losses in the temporal lobes were
associated with more severe positive symptoms
– More rapid gray matter losses in the frontal lobes were
strongly correlated with the severity of negative symptoms
• PET scans of brain activity during schizophrenic
hallucinations reveal activity in the left auditory and visual
areas of the brain, but not in the frontal lobe, which is
normally involved in organized thought processes.
The Shrinking of the Schizophrenic Brain
Among adolescents who suffer a relatively rare
childhood - onset schizophrenia, MRI scans by Paul
Thompson and his colleagues (2001) revealed a muchgreater-than-normal loss of cerebral cortex tissue
between the ages of 13 and 18
The Schizophrenic Brain
Doctors view X-rays of the brains of identical twins, one of whom has
schizophrenia. The X-ray of the schizophrenic twin shows shrinkage of
the brain tissue and an accumulation of cerebrospinal fluid.
Click HERE or on the
box to the Right to view.
The Schizophrenic Brain: Questions
1.
What does the difference in brain structures of these identical
twins indicate about the cause of brain abnormality and
schizophrenia in this case?
2.
Research suggests that prenatal viral infection may play a role
in schizophrenia. Suggest some ways in which this hypothesis
could be tested.
3.
What types of studies could look into the possible genetic
factors in development of schizophrenia?
Not Just Biology at Fault
• Some people with schizophrenia do not
show brain structure abnormalities
• The evidence is correlational
• The kinds of brain abnormalities seen in
schizophrenia are also seen in other
mental disorders
POSSIBLE
ENVIRONMENTAL
FACTORS
Viral Infection Theory
• Might be caused by exposure to an influenza
virus or other viral infection during prenatal
development or shortly after birth
• Children whose mothers were exposed to a
flu virus during the second trimester of
pregnancy show an increased rate of
schizophrenia
• Schizophrenia occurs more often in people
who were born in the winter and spring
months, when upper respiratory infections are
most common
Malnutrition & Schizophrenia
Children who were in their mothers' wombs during the period of great
famine in China later developed schizophrenia at roughly twice the usual
rate. (Data from St. Clair & others, 2005.)
POSSIBLE
PSYCHOLOGICAL
FACTORS
Unhealthy Families
• Individuals who are genetically predisposed to
develop schizophrenia may be more
vulnerable to the effects of disturbed family
environments
Finnish Adoptive Family Study of
Schizophrenia
• Found that children whose biological mother had
schizophrenia had a much higher rate of schizophrenia
than did the control group when they were raised in a
psychologically disturbed adoptive family
• When raised in a psychologically healthy adoptive family,
they were no more likely than the control group to develop
schizophrenia.
• One-third of the adopted children with no genetic history of
schizophrenia developed symptoms of a serious
psychological disorder if they were raised in a
psychologically disturbed family environment
• Conclusion: a healthy psychological environment may
counteract a person’s inherited vulnerability for
schizophrenia, but a psychologically unhealthy family
environment can act as a catalyst for the onset of
Other Family Influences on
Schizophrenia
Family variables
– parental communication that is
disorganized, hard-to-follow, or highly
emotional
– expressed emotion
• highly critical, over-enmeshed families
Cultural Differences in
Schizophrenia
• Prevalence of symptoms is similar no matter
what the culture
• Less industrialized countries have better rates
of recovery than industrialized countries
– families tend to be less critical of the patients
– less use of antipsychotic medications, which may impair
full recovery
– think of it as transient, rather than chronic and lasting
disorder
Development Model of Schizophrenia
This model depicts
researchers'
understanding of the
contributions of genes,
environmental
experiences, and the
person's present neural
and behavioral condition
to the development of
schizophrenia and, in
some cases, its
progression into a
chronic condition. (Based
on a model depicted by
Tsuang & others, 2001,
p. 22.)
Summary of Schizophrenia
• Many biological factors seem involved
– heredity
– neurotransmitters
– brain structure abnormalities
• Family and cultural factors also important
• Combined model of schizophrenia
– biological predisposition combined with psychosocial
stressors leads to disorder
– Is schizophrenia the maladaptive coping behavior of a
biologically vulnerable person?