Schizophrenia

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Schizophrenia

• A Beautiful Mind

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What is schizophrenia?

• A psychotic disorder characterized by major
  disturbances in thought, emotion, behavior.
• Disordered thinking, ideas not logically related,
  perception attention is faulty flat affect.

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Prevalence of disorder

• Occurs in 1 of the general population.
• Men women effected equally.

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Onset of Schizophrenia

• Late adolescence young adulthood (20-30s).
• Occurs in men earlier than in women.

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Comorbidity

• Substance abuse occurs in 50 of schizophrenics.

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Symptomatology

• Characterized by disturbances in several major
  areas
• thought, perception, attention
• motor behavior
• affect (emotion)
• Life functioning

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Large variability in Schizophrenia

• No essential symptom must be present for a
  diagnosis of schizophrenia.

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A. Positive symptoms

• Excesses or distortions that are present, but
  shouldnt be.
• Disorganized speech
• Hallucinations
• Delusions

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1. Disorganized Speech

• Schizophrenics thoughts are fragmented and so are
  their speech patterns.
• The schizophrenic produces utterances that are
  loosely related to a theme and usually goes off
  topic easily.
• Loose associations

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Example

• My thoughts get all jumbled up. I start
  thinking or talking about something but I never
  get there. Instead, I wander off in the wrong
  direction and get caught up with all sorts of
  different things that may be connected with
  things I want to say but in a way I cant
  explain. People listening to me get more lost
  than I do...My trouble is that Ive got too many
  thoughts. You might think about something, lets
  say that ashtray and just think, oh yes, thats
  for putting my cigarette in, but I would think of
  it and then I would think of a dozen different
  things connected with it at the same time.
  (McGhie Chapman, 1961, p. 108)

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2. Delusions

• Fixed false beliefs that persist despite evidence
  to contrary.

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Types of Delusions

• 1. Delusions of persecution
• 2. Delusions of grandeur- belief one is
  famous/historical (God, President).
• 3. Thought insertionthoughts are implanted in
  their minds from outside source.

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Delusions contd.

• 4. Thought broadcasting- thoughts are
  broadcasted via TV or radio to the world.
• 5. Thought stealing-their thoughts are being
  stolen
• 6. Feelings being controlled-by other people.

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3. Hallucinations- false sensory experiences

• 1. Audible thoughts- patients report hearing
  their own thoughts spoken by another voice.
• 2. Arguing voices
• 3. Voices commenting-on schizophrenics behavior.

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B. Negative symptoms

• Behavioral deficits in emotion processing daily
  functioning.
• Symptoms endure beyond acute episodes.

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Examples

• Avolition-absence of interest in usual routines
  (grooming, hygiene)
• Alogia-poverty of speech (lacks content)
• Anhedonia-inability to experience pleasure
  (relationships, sex)
• Flat affect-no emotional response to stimuli

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Other symptoms

• 1. Catatonia-motor abnormalities.
• Unusual gestures made repeatedly with the limbs
  (arms, hands, etc.).
• Immobility, adopting odd postures for long
  periods of time.
• 2. Inappropriate affect laughing at
  inappropriate times (funerals)

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Criteria for DSM diagnosis

• 1. Patients with symptoms of a mood disorder are
  specifically excluded.
• 2. Patient must have disorder for at least 6
  months.
• One-month active phase-- two of the following
  must be present delusions, hallucinations,
  disorganized speech, grossly disorganized or
  catatonic behavior, and negative symptoms.

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Types of schizophrenia

• Disorganized schizophrenia
• Catatonic schizophrenia
• Paranoid schizophrenia
• Undifferentiated schizophrenia

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What causes schizophrenia?

• A. Is there a genetic link?
• Yes.

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Evidence for genetics.

• Family studies, twin studies, and adoption
  studies show a strong genetic diathesis for
  schizophrenia.

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Family studies Data

• Relation to index case with schizophrenia
• Spouse 1
• Grandchildren 2.84
• Nieces/nephews 2.65
• Children 9.35
• Siblings 7.30
• Dizygotic twins 12.08
• Monozygotic twins 44.30
• (100 identical)
• (Gottesman, McGuffin, and Farmer, 1987).

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Twin studies

• If genetic transmission alone accounted for
  schizophrenia, than the concordance rate for
  monozygotic twins should be 100.
• Its less than 50 (Cannon et al., 1998 Cardno et
  al., 1999).
• Environmental factors determine whether genotype
  is expressed.

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Adoption studies

• By studying children of schizophrenic mothers
  reared in adoptive parental homes, environmental
  factors are eliminated.

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Heston (1966) follow-up study

• Examined 47 people born (1915-1945) to
  schizophrenic mothers in a mental hospital.
• Babies separated from their mothers at birth
  reared by foster or adoptive parents.
• Fifty control Ss selected were also examined.

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Ss were followed until 1964.

• Assessment included clinical interviews,
• MMPI, IQ.
• Each S was examined by two psychiatrists
  Heston.
• None of the control Ss were diagnosed with
  schizophrenia, whereas 16.6 of children born to
  schizophrenic mothers were diagnosed with
  schizophrenia.

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B. Biochemical basis

• The dopamine hypothesis there is an excess of
  dopamine in the schizophrenic brain.
• Based on idea that drugs used to treat
  schizophrenia, reduce dopamine.
• Antipsychotic drugs are structurally similar to
  dopamine molecules and block dopamine receptors
  (D2).

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Problem with dopamine theory

• A major metabolite of dopamine (homovanillic acid
  (HVA) has not been found in greater amounts in
  patients with schizophrenia.
• Schizophrenics may have more dopamine receptors,
  not dopamine in brain.

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Postmortem studies

• On schizophrenics, show their brains have more
  dopamine receptors than aged-matched controls.
• Pet Scans have confirmed this.

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Dopamine pathways

• Excess dopamine activity relevant to
  schizophrenia is localized in the mesolimbic
  pathway.
• Antipsychotics alleviate positive symptoms by
  blocking dopamine receptors there thereby
  lowering activity in this neural system.

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Problems with dopamine hypothesis

• 1. Despite fact that antipsychotics work on
  blocking D2 receptors right away, there is a
  delay in the relief of positive symptoms.
• 2. Antipsychotics dont show therapeutic effects
  until dopamine receptor activity is below normal.
  
• 3. Other neurotransmitters may be involved.
• E.g, Serotonin.

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C. Environmental factors

• Severe dysfunctional family systems may play role
  in onset of disorder.