Sz- Neurodevelopmental hypothesis Flashcards
What are the key brain structural abnormalities found in people with schizophrenia?
Smaller overall brain volume
Enlarged ventricles
Abnormalities in:
Frontal lobes Temporal lobes Hypothalamus Hippocampus Basal ganglia Amygdala Prefrontal cortex
What does the neurodevelopmental hypothesis of schizophrenia suggest?
Schizophrenia results from abnormal brain development
Latent until early adulthood
Triggered by brain maturation
What have post-mortem studies revealed about the brains of people with schizophrenia?
Enlarged ventricles (most consistent finding)
Suggests brain cell loss
Supported by CAT scans (25% of patients show this)
What are ventricles and what does it mean if they are enlarged?
Fluid-filled cavities in the brain
Supply oxygen, blood, and remove waste
Enlargement implies brain tissue death around ventricles
How much larger are the ventricles in people with schizophrenia, and what symptoms might this explain?
Ventricles are approx. 15% larger
May explain:
Greater cognitive disturbances Poor response to drug therapy
What abnormalities are seen in subcortical temporal limbic areas in schizophrenia?
Reduced size of the hippocampus
Enlargement of basal ganglia Affects sensory filtering and motor function
How might the basal ganglia affect schizophrenia symptoms?
Enlarged basal ganglia
May cause motor dysfunction (e.g., cataleptic stupor)
What is the relationship between grey matter loss and schizophrenia symptoms?
More grey matter loss in frontal and temporal lobes
Linked to more severe symptoms
What brain abnormality is linked to reduced emotional expression in schizophrenia?
Smaller amygdala
Linked to flat affect or emotional blunting
How does prefrontal cortex dysfunction affect patients with schizophrenia?
Impairs:
Speech Decision-making Willed actions
Reductions in grey matter and metabolic activity
May lead to delusions due to poor logical processing
What is the role of Wernicke’s and Broca’s areas in schizophrenia?
Weakened connection between the two areas in SZ patients
May cause:
Hallucinations (misinterpreting inner speech) Language issues (poverty of speech, word salad)
What did twin studies show about brain structure differences in schizophrenia?
MZ twin with SZ had:
Larger ventricles Smaller anterior hypothalamus
SZ twin identifiable in 12/15 pairs (Suddath et al., 1990)
What did Mathalon et al. (2001) find regarding brain volume in schizophrenia?
Schizophrenic adults show faster reduction in total brain volume than controls
What is a major limitation in using enlarged ventricles as a physical cause of schizophrenia?
Enlarged ventricles also found in some non-schizophrenics
Therefore, not a definitive cause on its own
