Biological Explanations

Question 1

genetic

how do researchers understand the possibility of the genetic basis

Answer 1

family studies, comparing concordance rates

Question 2

genetic

there are multiple genes involves meaning SZ is ……

Answer 2

polygenic

Question 3

genetic

what does aetiologically heterogeneous mean

Answer 3

different combination of factors, including genetic variation that lead to the condition

Question 4

genetic

give a study that supports the role of genetics

Answer 4

riley and kendler

• lifetime risk of developing disorder is 1%
• risk is 10x higher if first degree relative has disorder

Question 5

genetic

give the family study that supports the role of genetics

Answer 5

gottesman

• concorance rate of 48% in MZ twins compared to 17% in DZ twins

Question 6

neural

whats the neurotransmitter associated with SZ

Answer 6

dopamine

Question 7

neural

explain the original dopamine hypothesis

Answer 7

• excess dopamine in subcortical areas of the brain - hyperdopaminergia
• linked with positive symproms

Question 8

neural

explain the updated dopamine hypothesis

Answer 8

• low dopamine in the brains cortex - hypodopaminergia
• linked to negative symptoms
• leads to subcortical hyperdopaminergia
• so both high and low levels of DA in different brain regions

Question 9

neural

what is the mesocortical pathway

Answer 9

• hypodopaminergia
• outer layer of brain - low DA
• negative symptoms

Question 10

neural

what is the mesolimbic pathway

Answer 10

• hyperdopaminergia
• inner layer of brain - high DA
• positive symptoms

Question 11

neural

give a study that supports the role of drug use in SZ

Answer 11

di forti et al

• increases risk of developing disorder is associated with smoking high levels of THC in teenage years

Question 12

neural

give a study that supports the role of trauma in SZ

Answer 12

• 67% of patients with psychotic conditions reported at least one childhood trauma

Question 13

neural

giver study that supports the role of dopamine

Answer 13

tenn et al

• used amphetamines, which icrease DA, to induce SZ like symptoms in rats
• then reduced them using drugs
• supports the hypothesis

Question 14

neural

what are the 3 brain abnormalities in people with schizophrenia

Answer 14

• enlarged ventricles
• smaller brain size
• reduces grey matter

Question 15

neural

in people with SZ, venticles become …….. . This leads to a reduction in …… which makes their brain …..

Answer 15

enlarged, grey matter, smaller

Question 16

evaluate the neural explanation

strength

Answer 16

• P - supporting evidence
• EG - tenn et al. Used amphetamines, which increase DA, to induce SZ like symptoms in rats
• EX - shows doppamine highly involved creating a causal link
• L - supports dopamine hypothesis, increases validity
• H - animal studies, not generalisable

Question 17

evaluate the neural explanation

limitation

Answer 17

• P - evidence is correlational
• Eg - brain studies show reduced grey matter and brain size in SZ patients
• Ex - these studies only study brain differences, we cannot tell wethere the abnormality cause the disorder
• L - causal relationship cannot be formed which decreases valdiity
• H - longitudinal imaging is beginning to track changes before onset which may clarify the causalm sequence

Question 18

evaluate the genetic explanation

strength

Answer 18

• P - supporting evidence
• EG - gottesman, concordance rate 48% in MZ twins compared to 17% in DZ twins
• EX - MZ twins share 100% of DNA indicating genetics raise a risk
• L - shows theres a strong genetic componenet which increases validity
• H - not 100% so other factors must be there

Question 19

evaluate the genetic explanation

limitation

Answer 19

• P - biological reductionism
• Eg - ignores factors like childhood trauma which affects most SZ patients (morkved at al)
• Ex - showes social and psychological causes are also important
• L - isnt a complete explanation and ignores preventable environmental causes
• H - have practical value such as identifying high risk individuals allowing for early intervention