The biological theory of schizophrenia

• -      Nature

  -      Deterministic

  -      Reductionist
• Many biological psychologists agree that there is a genetic basis to this particular mental health problem.
• If there is a gene for SZ then it is possible that it goes on to affect the brains of people who are diagnosed with it.
• Dopamine


  A neurotransmitter linked to movement, perception, attention and mood
• Too much dopamine can lead to erratic movements, hallucinations and delusions
• Dopaminergic neurons transmit dopamine


  Fire too easily or too often
• Too much dopamine

  Can lead to many of the symptoms of Schizophrenia (SZ)
• D2 receptors

  Receptors on certain neurons that bind dopamine
• People with SZ seem to have an unusually high number of dopamine (D2) receptors on certain neurons
• High number of dopamine (D2) receptors

  Results in more dopamine binding and therefore more neurons firing across synapses
• More neurons firing across synapses
• When scanned


  An individual with SZ brain will look different to a healthy individual
• Blood flow is lower in the pre-frontal cortex
• Pre-frontal cortex is less frequently activated when certain tasks are carried out


  Appears to be defective in SZ
• Pre-frontal cortex


  Acts as the control centre of the brain
• This defective pre-frontal cortex may explain why these individuals lose control over their psychological functioning
• Temporal lobes are also lower in volume
• Hippocampus


  Has a role in formation of memories and the emotions that go with them
• Hippocampus is smaller in volume in people with SZ
• The more severe the disorder

  The more delegated the hippocampus is
• Some of this neurological damage in people with SZ may occur before they are born