Biological explanations (neural correlates)

• Ventricular differences:

  • Differences in the ventricles of the brain with people with schizophrenia, enlarged ventricles suggests damage to central areas of prefrontal cortex = negative symptoms in people with schizophrenia.
• Dopamine hypothesis:

  • Dopamine is important in the functioning of severe brain systems that may be implicated in symptoms of schizophrenia, (dopamine responsible for feelings for pleasure and thinking/movement).
  • High levels of dopamine in the sub cortex (excess dopamine receptors in Brocas area) associated with poverty of speech or auditory hallucinations.
  • Low levels of dopamine in prefrontal cortex = links to negative symptoms.
• strength of biological explanation:

  • P - research support
  • Ex - Johnstone = found schizophrenics had enlarged ventricles, while non-sufferers did not which suggests schizophrenia is related to loss of brain tissue.
  • Counter point - Weyandt = enlarged ventricles are associated with negative symptoms, doesn’t explain all symptoms/incidences of schizophrenia.
• Weakness of biological explanation:

  • P - fails to consider
  • Ex - same non-schizophrenics have enlarged ventricles, while not all schizophrenics do. Goes against idea of loss of brain tissue.
  • L - discredits neural correlates explanation.
• Strength:

  • P - scientific evidence
  • Ex - Ho et al = performed MRI scans on recent onset schizophrenics and the re-scanned 3yrs later. Found evidence of brain damage, in recent onset patients, worsened overtime (even on medication).
  • L - suggests brain damage increases in schizophrenics overtime.
• Strength:

  • P - practical implications
  • Ex - led to development of an effective treatment, new drugs such as clozapine, more effective that neuroleptics at relieving schizophrenic behaviour.
  • L - psychiatrists can understand, role played by neurotransmitters when treating different types of schizophrenics.