Biological explanations of SZ

Question 1

who studied concordance rates of genetics?

Answer 1

Gottesman (1991)

Question 2

What is the concordance rate of SZ in the ‘normal’ population?

Answer 2

1%

Question 3

What is the concordance rate of SZ for the offspring of 1 SZ grandparent?

Answer 3

5%

Question 4

What is the concordance rate for the offspring of 1 SZ parent?

Answer 4

13%

Question 5

What is the concordance rate for dizygotic twins?

Answer 5

17%

Question 6

What is the concordance rate of monozygotic twins?

Answer 6

48%

Question 7

What did Joseph (2004) calculate?

Answer 7

All pooled twin studies before 2001 showed a concordance rate of 40.4% for MZ twins and 7.4% for DZ twins

Question 8

What is the issue in concordance rates genetically?

Answer 8

similar genes = similar environment
esp true for MZ twins
but ethical issue of controlling ones environment

Question 9

What did Tienari (2000) study?

Answer 9

Finnish adoption study?

Question 10

What is the methodology of Tienari’s study?

Answer 10

164 adoptees whose biological mothers had SZ compared to a control of 197 adopted children with no SZ mother.
(all separated from mother by age 4, all aged 5-7)

Question 11

How many children in the control group developed SZ? Why is this significant?

Answer 11

4 (2%), similar to normal concordance therefore adoption is not a risk factor for SZ

Question 12

How many of children whose mothers had SZ developed it? What does this tell us about genetic factors?

Answer 12

11 (6.7%), genetics play a role in the development of the disorder and match concordance rates of prev studies

Question 13

What is a weakness of adoption studies?

Answer 13

Adoptees may have been selectively places in an environment similar to prev background, cannot be sure about genetics

Question 14

Who further analyzed Tienari and what did they find?

Answer 14

Wahlberg et al. (2000) found at-risk children did ‘better’ than those in less supportive environments (nurture vs nature)

Question 15

What is schizophrenia known as for its genetic makeup?

Answer 15

A polygenetic disorder.

Question 16

Who studied the genes of SZ?

Answer 16

Ripke et al. (2014) anaylsed more than 150,000 people and found over 100 genetic regions that contribute to SZ

Question 17

What gene is the most important atm?

Answer 17

DRD2 - gene encoding the dopamine receptor where all drugs are currently targeting

Question 18

What is the model called taking the nature and nurture of a disorder into consideration?

Answer 18

The diathesis-stress model

Question 19

What are the 4 parts to neural correlates?

Answer 19

The dopamine hypothesis
Areas of the brain
grey and white matter
ventricles

Question 20

What is the term for the excess of dopamine?

Answer 20

hyperdopaminergia

Question 21

What is the term for too little dopamine?

Answer 21

hypodopaminergia

Question 22

What happens when there is an excess of dopamine in Broca’s area?

Answer 22

responsible for speech production - associated with poverty of speech and/or auditory hallucinations

Question 23

What are the two drugs that increase dopaminergic activity?

Answer 23

Amphetamines
L-dopa

Question 24

What do amphetamines do?

Answer 24

release dopamine at central synapses, known to trigger SZ-like symptoms or make it worse in known SZ.

Question 25

What does L-dopa do?

Answer 25

L-dopa is converted into dopamine to relieve symptoms of parkinson’s disease

Question 26

What drugs decrease dopaminergic activity?

Answer 26

Clozapine
Neuroleptic drugs

Question 27

What does Clozapine do?

Answer 27

block dopamine which reduces symptoms

Question 28

Who researched the effectiveness of neuroleptic drugs?

Answer 28

Davidson & Neale (1996)

Question 29

Who proposed the revised dopamine hypothesis?

Answer 29

Davis and Kahn (1991)

Question 30

What is the revised dopamine hypothesis?

Answer 30

low levels (hypodopaminergia) in the prefrontal cortex (thinking and decision making) cause negative symptoms

Question 31

How is the prefrontal cortex related to SZ?

Answer 31

Mian area for executive control (planning, reasoning, judgement) is impaired in SZ

Question 32

How is the hippocampus related to SZ?

Answer 32

in temporal lobe, deficits lead to working memory impairments and central cognitive impairment (Mukai et al. 2015) c

Question 33

Why is grey matter significant in SZ?

Answer 33

Reduced grey matter especially in temporal and frontal lobes (Canon et al. 2014) found individuals at highs risk had steeper loss

Question 34

Why is white matter significant in SZ?

Answer 34

reduced myelination particularly in neural pathways PFC and hippocampus

Question 35

Why are ventricles significant in SZ?

Answer 35

Hartberg et al. (2011) found enlarged ventricles thought to be brain not developing properly.