12.3 Biological Explanations for Schizophrenia

• Individuals with a family history of schizophrenia are more likely to develop the disorder
• Monozygotic twins have higher concordance rates for schizophrenia than dizygotic twins.
• Monozygotic twins have a schizophrenia concordance rate of approximately 40-50%
• Hyperdopaminergia in the mesolimbic pathway is associated with positive symptoms of schizophrenia.
• Hypodopaminergia in the prefrontal cortex is associated with negative symptoms like flat affect
• Match the neuroanatomical abnormality with its effect:

  Enlarged ventricles ↔️ Loss of brain tissue

  Hippocampal abnormalities ↔️ Emotion regulation

  Prefrontal cortex changes ↔️ Decision-making
• What are neuroanatomical abnormalities associated with schizophrenia?

  Changes in brain structure
• Enlarged ventricles in the brain suggest a loss of brain tissue
• Changes in the prefrontal cortex affect decision-making and cognitive function in schizophrenia.
• What type of symptoms are associated with hippocampal abnormalities in schizophrenia?

  Memory and emotion regulation issues
• Reduced activity or volume in the prefrontal cortex can lead to cognitive impairments and decision-making issues
• Rank the concordance rates in twin studies for schizophrenia from highest to lowest.

  1️⃣ Monozygotic twins

  2️⃣ Dizygotic twins
• Match the dopamine variation with the brain region involved and associated symptoms.

  Hyperdopaminergia ↔️ Mesolimbic pathway: Hallucinations, delusions

  Hypodopaminergia ↔️ Prefrontal cortex: Flat affect, social withdrawal
• Lower levels of glutamate in the prefrontal cortex can cause cognitive deficits in schizophrenia.
• What type of symptoms are associated with serotonin imbalances in schizophrenia?

  Mood and anxiety issues
• Neurotransmitter imbalances in schizophrenia interact with genetic factors and neuroanatomical abnormalities
• What are neuroanatomical abnormalities associated with schizophrenia?

  Changes in brain structure
• Enlarged ventricles in the brain suggest a loss of brain tissue
• Hippocampal abnormalities in schizophrenia affect memory and emotion regulation.
• What cognitive functions are affected by prefrontal cortex changes in schizophrenia?

  Decision-making and cognition
• Enlarged ventricles in the brain are associated with a loss of brain tissue
• Hippocampal abnormalities can lead to issues with memory and emotion regulation.
• How do changes in the prefrontal cortex affect individuals with schizophrenia?

  Impair cognitive function
• Match the brain region with its associated abnormality and effect:

  Ventricles ↔️ Enlarged | Loss of brain tissue

  Hippocampus ↔️ Abnormal structure | Memory, emotion regulation issues

  Prefrontal cortex ↔️ Reduced activity | Cognitive impairments
• Enlarged ventricles in schizophrenia may correlate with the severity of symptoms.
• What other biological factors are related to neuroanatomical abnormalities in schizophrenia?

  Genetic factors and dopamine hypothesis
• Neurodevelopmental abnormalities in schizophrenia occur during prenatal and early postnatal
• Order the key concepts related to neurodevelopmental abnormalities in schizophrenia:

  1️⃣ Brain Development

  2️⃣ Neuronal Migration

  3️⃣ Genetic Factors

  4️⃣ Environmental Factors
• Disruptions in brain development can lead to abnormal neural networks in schizophrenia.
• What role do genetic factors play in neurodevelopmental abnormalities?

  Increase risk of abnormalities
• Prenatal exposure to the influenza virus can disrupt neuronal migration