Biological explanation for Schizophrenia- neural correlates

Question 1

The dopamine 60s hypothesis suggested sz is caused by what? A01

Answer 1

A chemical imbalance in the brain linked to the neurotransmitters

Question 2

What did the 60s initial dopamine focus on? A01

Answer 2

Brains of patients with Sz have excess dopamine
- abnormally high levels of D2 receptors
- leading to positive symptoms of Sz

Question 3

The revised dopamine hypothesis suggests sz is caused by what? A01-

Answer 3

-seems to be increased D2 receptor activities in the Mesolimbic pathway which raises dopamine

BUT ALSO
- reduced dopamine activity e.g. reduced D1 receptor activity in mesocortical pathway is linked to negative symptoms

Question 4

Other neural correlates explanations: Animal research by Holloway 2013

Answer 4

• maternal stress during pregnancy alters expression of serotonin and glutamate receptors : leading to sz like symptoms in adult mice
  = show importance of early environmental factors in the development of sz

Question 5

The dopamine hypothesis A03- strengths

Answer 5

• supported by effects of other drugs
  - eg. Amphetamines can cause excess dopamine- symptoms of psychosis (positive)
• brain research
  • with sz have differences in brain like grey matter in front and temporal lobes
    
    • if changes happen at early age: link t
      sensitivity to dopamine

Question 6

The dopamine hypothesis A03- weakness

Answer 6

• reductionist
  
  • not taking into account social, environmental factors
  • eg. Stressful life event may trigger
• contradictory evidence for undergoing brain scans
  
  • Carlsson - in brain scans, humans feel pressure likely to respond different from normal
    - brain scan findings not have validity if not taking situational factors into account