Biological Explanations

Question 1

What is the genetic explanation

Answer 1

Genes that consist of DNA strands contain instructions for physical/ psychological features

Question 2

What is one neural explanation

Answer 2

Structure and activity of the brain

Question 3

Family studies

Answer 3

( Gottesman 1991)
Risk op schizophrenia increases when there is a genetically similar relative with it
→ genes play a role

Question 4

Mutation

Answer 4

Schizophrenia could be the result of a mutation of parental
Brown (2002) found a positive correlation between parental age and risk of schizophrenia
- fathers under 25= 0.7%
- fathers over 50=2%

Question 5

Brain structures

Answer 5

Prefrontal cortex- helps to think logically and organise thoughts (schizophrenics have low activity in this area)
Amygdala- basic feelings like fear, lust, hunger (smaller in schizophrenics causing loss of emotion)

Question 6

Candidate genes

Answer 6

Ripke (2013) looked at genetic makeup of 37000 schizophrenic patients compared to 113000 controls
-found 108 genetic variations with increased risk
- schizophrenia is aetiologically heterogenous so different variations will cause schizophrenia in different people

Question 8

Dopamine hypothesis

Answer 8

Seeman (1987) antipsychotics lead to symptoms similar to Parkinson’s (low dopamine)
-could be due to hyperdopaminergia
David (1991) proposed hypodopaminergia
-cortical hypodopaminergia can lead to subcortical hyperdopaminergia

Question 9

AO3 research support

Answer 9

Family studies show risk increases with genetic similarity to family member
-tienari (2004) adoption studies- biological children of those with schizophrenia are at risk even if they grow up with an adoptive family
-hilker (2018) concordance rates, 33% monozygotic, 7% dizygotic

Question 10

AO3 environmental factors

Answer 10

-biological= birth complications (Morgan 2017)
Smoking cannabis (di forti 2015)
-psychological= childhood trauma
Mørkved (2017) 67% with schizophrenia had trauma compared to 38% in control
-> genetic factors are not the sole explanation

Question 11

AO3 genetic counselling

Answer 11

-if a patient has a relative with schizophrenia their child is at risk of developing it
However risk estimate is just an average and won’t reflect the individual

Question 12

AO3 evidence for dopamine

Answer 12

• curren (2004) amphetamines increase dopamine and worsen symptoms in people with schizophrenia and induce symptoms in those without
• tauscher (2014) antipsychotics reduce dopamine activity and intensity of symptoms
  Candidate genes act on dopamine production and receptors

Question 13

What is glutamate

Answer 13

An excitatory neurotransmitter involved in 90% of all excitatory functions of the brain, needed to keep brain functioning normally

Question 14

AO3 Role of glutamate

Answer 14

McCutcheon (2020) post mottem and live scanning found raised levels of glutamate in several brain regions of people with schizophrenia
-several candidate genes are involved in the production of glutamate