Schizophrenia - Biological Explanations

Question 1

Diathesis stress model researcher?

Answer 1

Gottesman and Reilley

Question 2

Gottesman and Reilley?

Answer 2

Many people have a biological predisposition for SZ which is triggered by psychological stressors

Question 3

Biological explanations for SZ?

Answer 3

Genetic factors and the dopamine hypothesis

Question 4

Genetic factors are looked at in…

Answer 4

family studies, twin studies and adoption studies

Question 5

Family study on SZ?

Answer 5

Gottesman

Question 6

Gottesman?

Answer 6

46% chance if both parents had SZ, 13% if one parent, 9% if a sibling had it and 1% chance for general population (40 european studies)

Question 7

Kety et al? (f)

Answer 7

20+ year study diagnosed SZ in 16.2% of the high risk group (mothers with SZ) and 1.9% of the low risk group, even when matched

Question 8

Twin study on SZ?

Answer 8

Gottesman and Shields

Question 9

Gottesman and Shields?

Answer 9

42% concordance rate for hospitalisation and diagnosis for MZ twins, 9% for DZ twins (57 twin pairs)

Question 10

Adoption study on SZ?

Answer 10

Kety et al

Question 11

Kety et al? (a)

Answer 11

High rates of diagnosis for chronic SZ in adoptees whose parents had the same diagnosis, despite being adopted by ‘healthy’ parents

Question 12

Weaknesses of genetic factors in SZ?

Answer 12

Methodological problems
Reductionist
Ignores nurture

Question 13

Strengths of genetic factors in SZ?

Answer 13

Support

Question 14

Supporting evidence for genetic factors in SZ?

Answer 14

Kety et al

Question 15

Methodological problems in genetic factors in SZ?

Answer 15

Most studies have broadened definition of SZ to include non-psychotic ‘SZ spectrum disorders’

Question 16

Research on SZ spectrum disorders?

Answer 16

Kety et al found no full cases of SZ among 1st degree relatives of children with SZ spectrum disorders

Question 17

Reductionism in genetic factors in SZ?

Answer 17

May be more to do with common rearing patterns or other factors such as EE

Question 18

Research on EE?

Answer 18

Kalafi and Torabi

Question 19

Kalafi and Torabi?

Answer 19

High EE was one of the main causes of SZ

Question 20

Ignoring nurture in genetic factors in SZ?

Answer 20

Joseph

Question 21

Joseph?

Answer 21

MZ twins treated more similarly, encounter more similar environments and experience more identity confusion

Question 22

Main belief of the dopamine hypothesis?

Answer 22

SZ results from an excess of dopamine activity at certain synaptic sites

Question 23

Reasons for excess of dopamine activity?

Answer 23

1. release of excess dopamine by presynaptic neurone firing too easily or too often
2. abnormally high excess of DZ receptors -> more dopamine binding -> more firing

Question 24

Research on dopamine hypothesis?

Answer 24

Comer

Question 25

Comer?

Answer 25

Dopamine neurones play a key role in guiding attention, so disturbances may lead to attention, perception and thought problems

Question 26

Ways of investigating dopamine hypothesis?

Answer 26

Aphetamines, antipsychotic drugs, parkinsons disease

Question 27

What approach does the dopamine hypothesis come from?

Answer 27

Biochemical

Question 28

What do amphetamines do?

Answer 28

Dopamine agonists - result in hallucinations and delusions

Question 29

What to antipsychotic drugs do?

Answer 29

Dopamine antagonists - eliminate SZ symptoms

Question 30

Research on parkinsons disease?

Answer 30

Grilly

Question 31

Grilly?

Answer 31

Sufferers of parkinsons disease have low levels of dopamine, so taking L-dopa to raise levels makes them develop side-effecs of SZ type symptoms

Question 32

Strengths of the dopamine hypothesis?

Answer 32

Support | Effective treatments

Question 33

Weaknesses of the dopamine hypothesis?

Answer 33

Reductionist Cause or effect? Weak evidence

Question 34

Support for dopamine hypothesis?

Answer 34

Seeman

Question 35

Seeman?

Answer 35

Increase in dopamine receptor density between 60-110% in SZs

Question 36

Effective treatments from the dopamine hypothesis?

Answer 36

Davis et al

Question 37

Davis et al?

Answer 37

55% relapse rates for those on placebo, 19% for those an antipsychotics

Question 38

Reductionism in dopamine hypothesis?

Answer 38

Vaughn and leff

Question 39

Vaughn and leff?

Answer 39

Antipsychotics only made a significant difference for those with high EE (53% relapse compared to 12%)

Question 40

Cause or effect in dopamine hypothesis?

Answer 40

Haracz

Question 41

Haracz?

Answer 41

Those who hadn't received medication had normal levels of dopamine in post-mortems

Question 42

Weak evidence for dopamine hypothesis?

Answer 42

Copolov and Crook

Question 43

Copolov and Crook?

Answer 43

PET scans yet to find convincing evidence