Biological explanation

Question 1

genetic factors

Family studies

Answer 1

Gottesman:
schiz is more popular for those who have relatives
the closer degree = the higher the risk

Question 2

graph

population =
siblings=
children=
1 parent schiz=
DZ=
MZ=

Answer 2

population= 1%
sibl= 9%
children= 13%
1 parent = 17%
DZ= 17%
MZ=48%

Question 3

family study
another guy

Answer 3

Kendler
first degree relatives of those who have schiz are 18 times more likely to develope it

Question 4

twin study

Answer 4

Joseph 2004
gathered data before 2001 abt schiz twins:
concordance rate for MZ = 40,4%
and for DZ = 7.4%

this shows that a great part in development of schiz playing genes
as DZ who share 50% of their genes, have a rate of only 7,4%

Question 5

Adoption studys

Answer 5

to see the differnce between genes and environment - adoption studies were used

Tienari 2000
164 adopted + biol.mom schiz = 6.7%
vs
197 adoptet + non-schiz biol mom = 2%

Question 6

schiz is

genes related

Answer 6

polygenic, which means more than 1 gene contributes to the disorder

Question 7

what did Ripke found

Answer 7

found 108 genetic variations of schiz

Question 8

eval 1 top

adoption

Answer 8

adoption studys have a very small unrepresentative sample

Question 9

eval 1 point

adoption

Answer 9

schiz = rare
adoption of schiz chilldren = more rare
so small sample is due to rarity
but it makes it harder to raly on findings, as they are hard to replicate
reliability is poor

Question 10

eval 1 tail

adoption

Answer 10

low reliability

Question 11

eval 2 top

mz + dz

Answer 11

crucial assumption is that mz + dz share environment

Question 12

eval 2 point

mz + dz

Answer 12

However, mz are treated more similarly, encounter similar environment and can experience ‘identity confusion’ more often than dz
according to Joseph

Question 13

eval 2 tail

mz + dz

Answer 13

suggesting differnces in rate can be due to environment

Question 14

eval 2 double

mz + dz

Answer 14

leading to the nature -nurture debate

Question 15

eval 3 top

fam

Answer 15

higher rate of risk when having relatives w schiz can be due to the dhared environment

Question 16

eval 3 point

fam

Answer 16

can be explained in terms of the fact that genetically similar fam members tend to spend more time together and are treated similarly due to the similarityin looks + behaviour

Question 17

eval 3 tail

fam

Answer 17

therefore it can affect the risk
this reffers to cousines, siblings, twins

Question 18

The Dopamine Hypothesis
explaine

Answer 18

Schiz have a higher number of dopamine receptors, causing over-activity and producing hallucinations
(D2)
Owen: increase in left amygdala, caudate nucleus and putamen

Question 19

what is Hyperdopaminergia

Answer 19

too much Dopamine in the subcortical and limbic regions
resulting in +ive symptoms

Question 20

how Hyperdopaminergia results in Hallucinationa and Delusions
explaine

Answer 20

interaction of excess D2 in the striatal area
and
processing sensory perceptions
results in
dopamine signals issues making the brain to ‘fill in the gaps’ with expectations rather than reality

Question 21

Hypodopaminergia is

Answer 21

less dopamine in the prefrontal cortex
results in -ive symptoms

Question 22

how Hypodopaminergia results in -ive symptoms
explaine

Answer 22

low level of D1 result in a less adequate stimulation of areas of motivation, reward (prefrontal cortex)
resulting in Auhedonia, Alogia

and

dopamine in Substantia nigra triggers physyical movements (including face), resulting in alogia and psychomotor disturbances

Question 23

what is revised dopamine hypothesis
+ two ppl

Answer 23

David and Kahn
increased dop. in the mesolimbic pathway (were the 5 senses are) = +ive symptoms

deficit of dop. in the mesocortical pathway = -ive symptoms + links to the prefrontal cortex

Question 24

Amphetamine is

Answer 24

dopamine agonist stimulates nerve cells containing dop
if it is given to a ‘normal’ person = risk of developing +ive symptoms episode which disapear after

Question 25

Antipsychotic drugs are

Answer 25

block dopamine activity by reducing activity in neural pathway eliminating hallucinations and delusions proving the importance of dopamine

Question 26

eval 1 top

Answer 26

evidence for a biological explanation comes form the successfull drug treatment

Question 27

eval 1 point | evidence form the successfull drug treatment

Answer 27

Leucht et al 2013 meta analysis of 212 studies: all antipsychotic drug were significantly more effective than placebo in the treatment of both types of symptoms achieved by reducing effects of dopamine

Question 28

eval 1 tail | evidence form the successfull drug treatment

Answer 28

this shows the importance of dopamine and its role in schiz. prooving the importnace of biological explanation

Question 29

eval 2 top | against dop hyp

Answer 29

Noll claims there are strong evidance against both hypothesis

Question 30

eval 2 point | against dop hyp

Answer 30

1/3 of thos who take antipsychotic drugs **don't** have their symptoms improved and in some ppl symptoms are present despite normall level of dopamine

Question 31

eval 2 tail | against dop hyp

Answer 31

this shows biological is still incomplete and requires more research, as dopamine isn't the only neurotransmitter that contributes to the symptoms

Question 32

neural correlates in schiz suggest

Answer 32

that structures in the brain are associated with the positive and negative symptoms

Question 33

ventricles -researcher-

Answer 33

Torrey 2002 ventricles in the brain are 15% larger schiz brain weigh leass than in neurotypical and a link hasa been found between enlarged ventricals and loss of grey matter (which is involved in movement, memories and emotions)

Question 34

research by .... et al 1990 to support ventricles

Answer 34

Suddath 15 pairs of twins (one of twins - schiz) 12/15 had significant ventricular size diff. on MRI scans these differences weren't present in the control group

Question 35

# neural correlates in the prefrontal cortex... and what it leads to?

Answer 35

dusfunction of Dorsolateral prefrontal cortical - underlying assumption for thought dissorder leads to: poor performance in tasks that require attention, working memory, cognitive flexibility

Question 36

research supporting the disfucntion of dersolateral prefrontal cortical

Answer 36

meta analysis of MRI: reaffirmed that Dorsolateral Prefrontal Cortical is a hotsop for reduced Grey matter

Question 37

what else is reduced in schiz brain ? | (smth other than grey matter)

Answer 37

white matter on the neural pathway between PFC and hippocumpus

Question 38

eval 1 top | neural correlates

Answer 38

supporting evidences from meta-analysis by Vita et al

Question 39

eval 1 point | neural correlates

Answer 39

19 studies, Comparison w normals. noticed huge reduction in grey matter, especially at the 1st stage

Question 40

eval 1 tail | neural correlates

Answer 40

reduction was seen specifically in frontal, temporal and parietal lobes suggesting the biologcial input into schiz however, it can be that these changes are actually not causing schiz. it can be schiz causing these changes . correleation isnt causation

Question 41

eval 2 top | neural correlates

Answer 41

early intervention can prevent from the development of disorder

Question 42

eval 2 point | neural correlates

Answer 42

the concept of 'treatment as prevention' used by North American PL study. they are using diff. assesment to predict the risk of schiz development

Question 43

eval 2 tail | neural correlates

Answer 43

knowing that researchers can prevent loss of brain tissue and treat 'at-risk' patients early on this supports the usefulness of biological explanation and shows how it can be used to improve ppls lifes. and at the same time contribute to the economy