Schizophrenia

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Schizophrenia
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Positive Symptoms

• First Rank Symptoms
• In Britain, schizophrenia is only diagnosed in
  the presence of one of the following first rank
  symptoms (disturbances of subjective experience
  as reported verbally by the individual).
• 1) Disturbance of thought the belief that
  thoughts are being inserted into the individuals
  mind from outside (thought insertion) or removed
  from their mind by external forces (thought
  withdrawal), or that their thoughts are being
  made known to others (thought broadcasting).
• 2) Hallucinations (the experience of sensory
  stimuli which are not present)
• Auditory (the most common). Voices offer a
  commentary on the individual's behaviour "he is
  eating his dinner"
• make disparaging remarks about him "he eats like
  a pig "give him commands "put the knife on the
  plate".
• Voices may be a distortion of environmental
  noises (fridge or radiator noises interpreted as
  whispering) or projections of the individual's
  own thoughts (thoughts may enter the individuals
  internal speech loop or even become spoken aloud
  without the individual realising that the
  thoughts / speech are his own (malfunction of the
  feedback loop).
• Somatic e.g. experience of electric shocks to the
  fingertips.

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Positive Symptoms

• 3) Delusions (beliefs which individuals are
  firmly convinced are true, regardless of evidence
  to the contrary). These can come in-
• Delusions of grandeur the individual is someone
  important or powerful (Christ, Napoleon).
• Delusions of persecution the individual is being
  conspired against/interfered with by other people
  or organisations (M15, the Mafia).
• Delusions of reference the individual believes
  that unrelated events have personal significance
  e.g. the words of a song refer to them
  personally.
• Other common delusions the belief that nothing
  really exists and all things are simply shadows
  the belief that one has been dead for years and
  it is observing the world from afar.

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Negative Symptoms

• Emotional Disturbance
• a) Blunting apparent indifference to events
  which would normally provoke a strong emotional
  reaction.
• b) Inappropriate Affect e.g. laughing when told
  bad news, reacting angrily if offered a gift.
• c) Flattened Affect absence of emotional
  expression, speech is in monotone, no mobility of
  facial features, vacant gaze.
• Lack of Volition
• Loss of interest in the external and social
  world. Loss of drive.
• Inability to act, including inability to perform
  everyday living activities e.g. washing, cooking.
• Disordered Sense of Self
• Sufferer has little idea who he / she is and has
  no ego-boundaries. The sufferer displays autism,
  and lives in a fantasy world, taking no notice of
  the world around them.

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Explanations Biologicalvs Psychological
Nature vs Nurture
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Diathesis Stress Model

• No-one believes Schizophrenia is completely
  caused by either genes or the environment.
• There must be an INTERACTION between the two.
• Diathesis Genetic tendency to develop
  schizophrenia.
• Stress Environmental trigger that starts it
  off.

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Diathesis Stress Model

• Interesting Questions
• What is More important nature or nurture?
• How do we separate the effects of nature and
  nurture? (People who share genes tend to share
  the same environment)

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Biological Explanations

• Genetics
• Bio chemicals
• Brain Structure

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Genetics Twin Studies(AO1)

• Gottesman 1991 suggests that schizophrenia is
  inherited through genes.
• QUESTIONS
• Why study identical twins?
• What would you expect to find?

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Genetics Family Studies(AO1)

• Gottesman also concluded that if both your
  parents suffer from Schizophrenia, you have a 46
  chance of developing it yourself (compared to a
  1 chance of someone selected at random will
  suffer)
• The more genetically similar relatives are, the
  more concordance is found.

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Schizophrenia genetics
www.psychlotron.org.uk
Source Gottesman (1991)
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Genetics Adoption Studies(AO1)

• QUESTION
• Why did Kety et al (1988) study adopted people
  with schizophrenia?
• He found
• 14 biological relatives developed schizophrenia
• 2.7 adopted relatives developed schizophrenia
• QUESTION what does this suggest?

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Molecular Biology(AO1)

• Miyakawa et al (2003) switched off an immune
  system gene in a mouse
• What happened?
• How can this lead to new drug developments?

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Evaluating Genetic Explanations(AO2)

• Make two evaluation points about
• Family Studies
• Adoption Studies
• Molecular Biology

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Biochemical Factors The Dopamine Hypothesis

• This theory claims that excessive amounts of
  dopamine or an oversensitivity of the brain to
  dopamine is the cause of schizophrenia
• There are 3 pieces of evidence to support this
• 1. Drugs which block dopamine (Phenothaiazines)
  reduce the symptoms of schizophrenia.

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The Dopamine Hypothesis -

• 2. L-Dopa a drug for Parkinsons disease
  actually increases dopamine this in turn can
  produce symptoms of schizophrenia.
• 3. Post mortems of schizophrenics, show an
  increase of dopamine in parts of the brain.
  (Seeman 1987)

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Schizophrenia dopamine

• The dopamine hypothesis
• Schizophrenia is caused by excessive DA activity.
  
• This causes abnormal functioning of DA-dependent
  brain systems, resulting in schizophrenic
  symptoms
• DA can increase or decrease brain activity
  depending on the system youre looking at

psychlotron.org.uk
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The dopamine hypothesis

• Wise Stein (1973) report abnormally low levels
  of DBH in post-mortem studies of S patients
• Would suggest abnormally high DA activity as DBH
  needed to break DA down
• Cant rule out cause of death or post-mortem
  changes as a source or error

psychlotron.org.uk
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The dopamine hypothesis

• Overdose of amphetamine (DA agonist) can produce
  S-like symptoms. S patients have abnormally
  large responses to low amphetamine doses
• Suggests a role for DA in S symptoms
• Suggests that the issue is over-sensitivity to DA
  rather than excessive DA levels

psychlotron.org.uk
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The dopamine hypothesis

• S symptoms can be treated with DA antagonists
  (e.g. chlorpromazine). These are effective in
  60 of cases with more impact on positive
  symptoms.
• Supports role of DA again, but what about 40 who
  dont respond?
• Lack of impact on negative symptoms hints at two
  separate syndromes

psychlotron.org.uk
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Evaluating the Dopamine Hypothesis(AO2)

• Write six evaluation points, examining the
  evidence on your handout.

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Brain Structure

• People with schizophrenia have abnormally large
  ventricles in the brain. Ventricles are fluid
  filled cavities. This means that the brains of
  schizophrenics are lighter than normal.

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Brain Structure Evidence

• Andreasen et 1990 conducted a controlled CAT
  scan study and found significant enlargement of
  the ventricles in schizophrenics compared to
  controls.

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Biological explanations

• No one is sure if there are a range of different
  biological problems which together cause
  schizophrenia or if there are actually different
  types of schizophrenia which may have different
  causes.

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Two Syndrome Hypothesis - Crow 1985 there maybe
two different types!

• Type one - genetically inherited associated with
  dopamine characterised by positive symptoms.
• Type Two Neurodevelopmental disorder to do
  with Brain structure characterised by negative
  symptoms.

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Positive and Negative Symptoms

• Positive - hallucinations, delusions, racing
  thoughts (high)
• Negative - apathy, lack of emotion, poor social
  functioning, and cognitive disorganized etc.
  (low).

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Advantages of the biological model

• 1. It is scientific
• 2. It offers drug therapy
• 3. It may offer a cure

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Problems with biological model

• 1. There is conflicting biological evidence
• 2. We cannot be sure that schizophrenia is one
  disorder
• 3. We cannot prove cause and effect
• 4. There are alternative explanations
• 5. It is difficult to separate out genes from
  social situations.
• 6. Genetic inheritance it is only a predictor of
  a predisposition and is not a predictor of
  actually getting the disorder.
• 7. Biological explanations are therefore
  incomplete

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Psychological Explanations for schizophrenia -
Behaviourism

• Behaviourists would look not only at how patients
  learn to develop faulty behaviour patterns but
  also at how they learn faulty thinking!

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Operant Conditioning schizophrenia

• Children who do not receive reinforcement for
  normal behaviour may put inappropriate
  attention into irrelevant environmental cues.
• For example paying attention to the sound of a
  word rather than meaning.

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• This behaviour will eventually appear weird to
  others.
• These strange behaviours may be rewarded by
  attention and sympathy and so are reinforced.
• This can continue until the behaviour becomes
  labelled as schizophrenic. (Rosenhan)

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Punishment and schizophrenia

• Another suggestion is that early experience of
  punishment may lead the child to retreat into a
  rewarding inner world. Others then label them as
  odd or strange. (Think MPD and Eve White)

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Social learning schizophrenia

• Families affect social learning.
• Bizarre behaviour by parents is copied by
  children.
• Parents then reinforce this behaviour, until
  eventually the child acquires the label of being
  schizophrenic.

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Evidence to support operant conditioning
reinforcement in schizophrenia

• Ullman (1969) observed mental health nurses in
  their interactions with patients and concluded
  that staff actually reinforce schizophrenic
  behaviour by giving more attention to these
  patients thus increasing the likelihood of the
  behaviour reoccurring.

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Evidence for Social learning and schizophrenia

• Roder et al. (2002) used social skills training
  techniques to help schizophrenics. The success
  of training programmes in teaching new skills and
  reintegrating schizophrenics back into the
  community suggests that these are social skills
  that schizophrenics failed to learn in the first
  place.

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The Cognitive Model of Schizophrenia

• Beck explains the disorder is due to genetic,
  environmental, psychosocial and cognitive factors
  which all interact.
• The cognitive model of schizophrenia can,
  therefore, be considered a holistic approach to
  the disorder.

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The Stress diathesis ModelCognitive

• Genetic abnormalities create a predisposition for
  the development of the disorder, but the disorder
  only develops in response to stress. The more
  stressors accumulate, the greater the risk a
  susceptible person has of developing
  schizophrenia.
• Stress affects the development of the hippocampus
  which in turn affects cognitive skills.

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The Diathesis-Stress Model

• A person with a predisposition to develop
  schizophrenia has limited cognitive resources due
  to biological factors such as high dopamine,
  larger ventricles and poor hippocampus
  development. However, as long as life is
  relatively stress-free they are able to
  compensate for this and their behaviour appears
  normal.

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Cognitive treatments for schizophrenia

• Bradshaw 1998 (Case Study)
• Bradshaw used CBT in the long-term outpatient
  care of a young woman with schizophrenia.
  Measures of psychosocial functioning, severity of
  symptoms, compliance with treatment and
  reductions in hospital visits were used to
  assess change over the 3- year treatment period
  and at 1-year follow-up. Results indicate
  considerable improvement in all outcomes.

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Evaluation for psychological explanations for
schizophrenia

• Behavioural explanations lack conviction. It is
  highly unlikely we can learn schizophrenia!
• Behaviourist explanations may explain
  maintenance, or differences in ability to deal
  with the disorder, rather than being a cause of
  the disorder
• The cognitive explanation is however more
  holistic and complete (and therefore less
  reductionist) than either the biological or
  behaviourist model

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Evaluation

• Psychological models are very useful in treatment
  programmes. Giving patients the cognitive skills
  to deal with their disorder can reduce the
  symptoms.
• Behavioural techniques can help patients fit into
  the community by improving social skills.
• Cognitive / behavioural therapies are less
  unethical, and have no side effects compared to
  drug therapy. They are however expensive.

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Evaluation

• On the other hand, some patients are just too
  sick to responds to psychological therapy and are
  also too sick to self report about their
  experiences, making this area very difficult to
  investigate with any reliability or validity.
• Psychological explanations are unlikely to lead
  to a cure!