9A. An Introduction to Schizophrenia

• What is schizophrenia?

  A chronic mental health condition with psychotic symptoms
• Who coined the term schizophrenia and when?

  Bleuler in 1908
• What percentage of the population is affected by schizophrenia?

  0.5-1%
• When does schizophrenia typically onset for males and females?

  Adolescence and early 20s for males; late 20s to 30s for females
• How does the severity of schizophrenia differ between genders?

  Less severe in females with less pronounced symptoms
• What are the three key categories of schizophrenia symptoms?

  • Positive symptoms
  • Negative symptoms
  • Cognitive deficits
• What are examples of positive symptoms of schizophrenia?

  • Hallucinations
  • Delusions
  • Disordered thoughts
• What are examples of negative symptoms of schizophrenia?

  • Reduced speech (alogia)
  • Social withdrawal (asociality)
  • Lack of emotion
  • Avolition
  • Anhedonia
• Where would we expect to see cognitive deficits in schizophrenia?

  • Memory
  • Attention
  • Planning
  • Decision making
• What are the typical phases in the course of schizophrenia?

  1. Premorbid phase
  2. Prodromal phase
  3. Psychotic phase
  4. Stable phase
• What characterizes the premorbid phase of schizophrenia?

  Begins in childhood with no symptoms
• What occurs during the prodromal phase of schizophrenia?

  Brief positive symptoms and functional decline
• What defines the psychotic phase of schizophrenia?

  Florid positive symptoms in adolescence or young adulthood
• What happens during the stable phase of schizophrenia?

  Negative symptoms, social deficits, and functional decline
• What are the possible courses of schizophrenia after the initial episode?

  • 8%: several episodes, no return to normality
  • 22%: one episode, return to normality
  • 35%: several episodes, no return to normality
  • 38%: several episodes, increasing impairment
• What is the current focus in schizophrenia research?

  Identifying clinically high-risk individuals before onset
• What negative outcomes can result from having schizophrenia?

  • Increased family stress
  • Shame
  • Abuse
  • Unemployment
  • Poverty
  • Homelessness
  • Incarceration
  • Recurrent hospitalizations
  • High comorbidity with medical illness and depression
  • Increased suicide attempts (5-10% completion rate)
  • Reduced life expectancy by 1-3 decades
• How has the role of genes in schizophrenia been examined?

  Examined through family, adoption, and twin studies
• What is the concordance rate for DZ twins in schizophrenia?

  17%
• What is the concordance rate for MZ twins in schizophrenia?

  48%
• What is the heritability percentage range for schizophrenia?

  70-80%
• What is the nature of genetic influence on schizophrenia?

  Considered polygenic with no single gene identified
• What are the two options for genetic influence on schizophrenia?

  • Common variant: many variants with small effects
  • Rare variant: key gene DISC1 linked to development
• How does winter birth affect schizophrenia risk?

  Increases risk by 15%
• How does owning a cat in childhood affect schizophrenia risk?

  Increases risk by 15%
• What is the risk increase for complications at birth regarding schizophrenia?

  Increases risk by 53%
• How does urban upbringing affect schizophrenia risk?

  Increases risk by 85%
• What is the risk increase for infection during pregnancy regarding schizophrenia?

  Increases risk by 182%
• How do adverse childhood experiences affect schizophrenia risk?

  They increase the risk
• What gross changes in the brain are associated with schizophrenia?

  • Ventricles are 15% larger
  • Loss of grey matter in patients and relatives
• What brain functioning changes are associated with schizophrenia?

  • Reduced frontal lobe activity relates to negative symptoms
  • Ventricular changes correlate with cognitive ability
  • Increased activity in hearing areas during hallucinations
• What does the dopamine hypothesis state about schizophrenia?

  Altered dopamine levels cause symptoms
• What is associated with positive symptoms in schizophrenia?

  Increased dopamine in mesolimbic pathways
• What is linked to negative and cognitive symptoms in schizophrenia?

  Decreased dopamine in mesocortical pathways
• How do dopamine antagonists affect psychotic symptoms?

  They reduce psychotic symptoms
• What can drugs that increase dopamine do?

  Induce psychotic symptoms
• What other neurotransmitters have been implicated in schizophrenia?

  • Glutamate
  • Serotonin
  • Acetylcholine
• What are the effects of low glutamate in schizophrenia patients?

  • Low CSF levels
  • PCP or ketamine produce SZ-like symptoms
  • Post-mortem changes in glutamate transmission
  • Genes can influence glutamate transmission
  • Reduced NMDA receptor binding
• How does serotonin relate to schizophrenia?

  • Modulates dopamine
  • Linked to negative symptoms
  • Newer antipsychotics act on serotonin
• What is the relationship between nicotine and schizophrenia?

  • High smoking rates (90% in SZ)
  • Nicotine may treat cognitive problems
  • Withdrawal exacerbates cognitive impairments