Schizophrenia

1
Schizophrenia
Onset can be slow or sudden Typically exists
chronically Affects 1 of population Diagnosis
must have at least two symptoms for more that 1
month
2
Schizophrenia Symptoms

• Positive Symptoms (abnormal states)
• hallucinations (auditory, visual)
• delusions (grandeur, persecution)
• Negative Symptoms (insufficient functioning)
• avolition (inability to initiate/persist in
  activities)
• alogia (absence of speech)
• anhedonia (inability to experience pleasure)
• affective flattening (flat emotional response)
• Disorganized Symptoms
• inappropriate affect (laughing/crying at the
  wrong times)
• disorganized speech (illogical, rambling,
  tangential)
• disorganized behavior (catatonia,
  agitation/immobility)

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Schizophrenia Subtypes

• Paranoid Type
• hallucinations
• delusions
• Catatonic Type
• unusual motor responses
• remaining in a fixed position
• excessive activity or rigidity
• echoing words or movements of others
• Disorganized Type
• speech problems
• behavior problems
• flat or inappropriate affect

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Schizophrenia and Gender
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Schizophreni Genetic Risk by Relatedness

• The Evidence
• Family History
• Twin Studies
• monozygotic (50)
• same handed (92)
• dizygotic (15)
• both are carriers
• Adopted Children
• more like bioparents
• Single Gene?
• Probably not

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Brain Structure AbnormalitiesIncreased Lateral
Ventricles
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Brain Structure AbnormalitiesReduced Hippocampus
and Amygdala
Affected
Normal
Affected
Normal
8
Brain Structure AbnormalitiesHippocampal
Pyramidal Cell Disorganization
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Brain Structure AbnormalitiesAtypical Frontal
Lobe Functioning

• Evidence
• smaller forebrain
• smaller cerebral cortex
• smaller dorsolateral prefrontal cortex
• fewer cortical neurons
• smaller cortical neurons
• abnormal neuronal development
• neurons remain in white matter
• fail to arrange in neat order
• abnormal CAMs
• less metabolic activity
• hypofrontality
• failure to increase activity following task
• abnormal EEGs

10
Neurobehavioral Hypothesis

• Maternal/Fetal Evidence
• extensive maternal bleeding
• prolonged labor
• delivery complications
• low birth weight
• low head circumference
• body lengthbody weight
• multiparity
• Anectodal Evidence
• Dutch births during WWII
• Season of birth effect
• higher for winter pregnancies
• parallel with virus exposure

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Dopamine Hypothesis of Schizophrenia
Abnormal levels of Dopamine lead to the
schizophrenic symptoms

• 1. Amphetamine Psychosis
• Chronic users develop schizophrenic symptoms
• paranoia, delusions of persecution, auditory
  hallucinations
• Amphetamine exacerbates schizophrenic symptoms
• Amphetamines promote the release of
  catelcholamines
• particularly dopamine
• 2. Antipsychotic Drugs
• chlorapromazine is a dopamine antagonist and
  antipsychotic
• block specifically D2 and D4 receptors in the
  limbic system
• effectiveness is related to magnitude of blockade
• 3. Parkinsons Disease
• some patients receiving L-dopa become psychotic
• some schizophrenic patients on antipsychotics
  develop Parkinsons symptoms