Schizophrenia

1
Schizophrenia

• Symptoms, History, Etiology Treatment

2
Schizophrenia

• Psychotic disorder marked by disturbances in
  thought, emotion, behavior
• Positive symptoms excesses in behaviors
• Negative symptoms deficits in behaviors
• Other symptoms

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Positive Symptoms

• Disorganized speech (aka formal thought
  disorder)
• incoherent speech, loose associations,
  derailment
• Delusions beliefs that are contrary to reality
• Paranoia, thought insertion, strange bodily
  sensations, thought broadcasting, stolen
  thoughts, controlled by others
• Hallucinations sensory experiences in absence of
  environmental stimulation
• Auditory (most common hear voices)
• Visual

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Negative Symptoms

• Avolition apathy, lack of energy, lack of
  interest in usual activities
• Alogia poverty of speech, poverty of content
• Anhedonia inability to experience pleasure, lack
  of interest in recreation, failure to develop
  close relationships, lack of interest in sex
• Flat affect lack of response to emotional
  stimuli
• Asociality lack of social relationships

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Other symptoms

• Catatonia motor abnormalities, repetitive
  gestures, purposeful complex sequences of
  movements
• Catatonic immobility unusual postures retained
  for a long period of time
• Waxy flexibility another person can mold the
  persons limbs into postures that will be
  retained
• Inappropriate affect emotional responses out of
  context

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Schizophrenia categories

• Disorganized incoherent speech, flat or
  inappropriate affect, behavior without a goal,
  may lack basic hygiene skills
• Catatonic shift from catatonia to excitement,
  echolalia, oppositional behavior
• Paranoid prominent delusions (e.g. persecution,
  grandiosity, jealousy), auditory hallucinations,
  ideas of reference, agitation, argumentative,
  angry
• More alert, verbal, and responsive than other
  subtypes

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Interaction Effect for Schizophrenia

• Single Gene Model
• (just to illustrate point)
• Only combination of vulnerability plus stress
  produces schizophrenia
• Genetic specificity
• Environment only acts on vulnerables (e.g., 10
  of population)

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Multifactorial polygenic model

• Liability
• Specific genetic
• General genetic
• General environmental
• Threshold for schizophrenia

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Dopamine

• Phenothiazines are useful in treating Sz
• Side effects resemble Parkinsons symptoms
• Parkinsons results from low levels of Dopamine
• Phenothiazines as lowering Dopamine activity
• Sz as excess Dopamine activity
• Amphetamine psychosis
• Users present with paranoid Sz symptoms
• Due to amphetamines impact on Dopamine

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Excess vs. oversensitivity

• Do Szs have an excess of Dopamine?
• No, excess Dopamine metabolites not found in Szs
• Oversensitive Dopamine receptors?
• Postmortem exams of Szz show increased numbers
  of Dopamine receptors
• Related to positive symptoms of Sz
• Amphetamines worsen phenothiazines may help
  only positive symptoms of Sz
• Dopamine in different brain areas

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Brain pathways Dopamine
Brain injury prefrontal cortex
Dopamine Neuron under active in prefrontal cortex
Negative Symptoms of Sz
Positive Symptoms of Sz
Increase in Mesolimbic Dopamine released
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Complications in Da theory

• Phenothiazine timeline off
• Tolerance should develop, but does not
• Phenothiazines must produce deficit in Da to be
  effective
• Parkinsonian side effects
• Not effective for Sz if Da at normal levels
• Other NTs involved
• Serotonin, glutamate
• Unlikely that Da solely responsible
• Need broader biochemical net

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Brain abnormalities

• Postmortem studies
• Abnormal hippocampus, amygdala
• MRI, CT scans
• Enlarged lateral ventricles
• Reduced limbic structure volume
• Deterioration or atrophy in brain tissues
• Andreasens lab Brave New Brain
• Prefrontal cortex
• Atrophy, low metabolic activity
• Fetal exposure to virus

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Sz and SES

• Twice as likely to have Sz if low social class
• Replicated across cultures
• Cause or effect?
• Sociogenic hypothesis vs. social-selection theory
• Evidence mixed

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Sz and the family

• Schizophrenogenic mother
• Cold, domineering, rigid, rejecting mother
  thought to create Sz in the child through
  parenting style
• No support
• Supported differences in Sz families
• Vague communication style, high in conflict
• Expressed emotion critical comments hostility
• Patients in high EE families showed greater
  relapse
• 58 vs. 10
• Cause or effect of having Sz child?

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Risk factors for Sz

• Low IQ
• Delinquent and withdrawn in childhood
• Poorer motor skills
• Heightened negative affect
• High-risk method
• Kids from Sz mothers
• Negative sxs pregnancy birth complications
• Positive sxs family instability