Biological Explanations For Schizophrenia

Question 1

What is the key assumption for biological explanations of Sz?

Answer 1

• inheritable

Question 2

What are the 3 studies associated with the genetic explanation for Sz ?

Answer 2

• family studies
• twin studies
• adoption studies

Question 3

What is the family study?
• genetics

Answer 3

• 1% of general pop. has Sz with no blood relation to them.
• Gottesman
• meta- analysis
• reviewed 40 studies of family history of Sz
• found that the closer the relation to someone with Sz, the greater the risk of developing it is

Question 4

What is the adoption study?

Answer 4

• Tienari
  Found:
• 6.7% of adopted children w a Sz mother had the disorder themselves. Meaning they have predisposition
• 2% of adopted children with a non-Sz mother had it themselves
• suggests a genetic liability to Sz
• however, could adopted children be like there adopted mother ???

Question 5

What is the Twin study ?

Answer 5

• Gottesman
• meta- analysis of 40 studies
• MZ = 48% more likely
• DZ= 17% more likely
• There are problems with this study: it could be due to environmental factors as concordance rates aren’t 100% in MZ twins, even though their genetics are

Question 6

Evaluation of genetic explanations for Sz

Answer 6

+ scientific credibility

+ research support: twin, adoption & family studies

• methodology: only used small samples as it was difficult to find, meaning generalisation if difficult and therefore other explanations may have more validity

Question 7

What is the key assumption for the neural explanation of Sz?

Answer 7

• physical origin: what is going on in the brain with neural activity

Question 8

What is the dopamine hypothesis?

Answer 8

• states that excess of dopamine is associated with positive symptoms of schizophrenia
• due to abnormally high levels of DZ receptors on the receiving neurons
• results in dopamine binding
• so more neurons firing
• leads to positive symptoms

Question 9

What so the revised dopamine hypothesis?

Answer 9

• Davis & Kahn
• said positive symptoms are due to an excess of dopamine in brain
• said negative symptoms arise from a deficit of dopamine in pre-frontal cortex

Question 10

How does anti psychotic drugs help schizophrenia?

Answer 10

• they decrease dopaminergic activity
  By:
• blocking the activity of dopamine in brain
• by reducing activity in neural pathways, that use dopamine as the neurotransmitters
• this eliminates the symptoms that dopamine causes

Question 11

Evaluation of neural explanations

Answer 11

+ scientific credibility: offers empirical evidence E.g. PET scans of Sz patients

+ RWA: placebo effect rules out as they wouldn’t prescribe drugs if they didn’t work

• deterministic: not all schizophrenics have high dopamine, so suggests there’s other factors E.g. environmental