Biological explanations for schizophrenia - AO3

Question 1

What is a PECS paragraph for genetic explanations of SZ?

Answer 1

• P: Strength = research support
• E: Gottesman study, MZ = 48% vs DZ = 17. Hilker et al, MZ=33% vs DZ = 7%
• C: Not 100% for MZ twins; two thirds with SZ have no family member with SZ
• S: Must be other factors involved

Question 2

What is a limitation for genetic explanations for SZ?

Answer 2

• P: Limitation = environmental factors
• E: Psychological risk factors: childhood trauma could create vulnerability to mental health disorder
• E: Morkved et al. (2017): 67% of people with SZ or related psychotic disorders reported at least one childhood trauma (vs 38% matched group)
• L: Genetic factors alone cannot provide complete explanation for SZ

Question 3

What is a strength of the dopamine hypothesis?

Answer 3

• P: Strength = research support
• E: Tauscher et al. (2014) antipsychotics are effective in reducing symptoms
• E: Antipsychotics reduce dopamine levels
• L: Dopamine is correlated with the symptoms of schizophrenia

Question 4

What is a limitation of the dopamine theory?

Answer 4

• P: Limitation = evidence for glutamate
• E: Post morterms and live brain scans find raised levels of nuerotransmitter glutamate (McCutcheron et al. 2020)
• E: Several candidate genes also linked to glutamate production
• L: Equally strong case for role of other neurotransmitters