biological explanations for schizophrenia

Question 1

What are the biological explanations for Schizophrenia?

Answer 1

. genetics
. neural correlates
. dopamine hypothesis

Question 2

Genetic theory

Answer 2

. genetic explanation states Sz is hereditary
. passed on from one generation to next through genes
. person born with genetic predisposition to Sz
. several maladaptive candidate genes (polygenic) - such as PCM1 - are involved - increase persons vulnerability
. studies shown 108 separate genetic variations associated with risk of developing Sz

Question 3

Gottesman’s twin study

Answer 3

. Gottesman (1991) studies 40 twins
. found concordance rate for monozygotic twins = 48%
. only 17% dizygotic twins
. so closer the genetic link more chance of developing Sz

Question 4

AO3 for genetic theory as an explanation for Sz: RTS Tierney

Answer 4

P - RTS role of genetics in development of Sz by Tierney
E - studies 155 adopted children had biological mothers with Sz
E - found concordance rate 10% - compared with 1% for adopted children no Sz parent
L provides significant support for role of genetics as explanation. of Sz - as SLT not been factor as children were adopted

Question 5

What is the idea of neural correlates?

Answer 5

. idea that abnormalities within specific brain areas may be associated with development of Sz
. brain scanning techniques (fMRI) used to compare brains of Sz with non-suffers - identify brain areas linked

Question 6

Neural correlates: brain structure or function

Answer 6

. one neural correlate of Sz = enlarged ventricles
. meta-analysis by Raz and Raz
. found over half people tested with Sz had increased ventricle size compared to control group
. enlarged ventricles associated with damage to central brain areas/pre-frontal cortex
. pushes on Broca’s area which produces spoken language so causes speech poverty
. damage associated with negative symptoms Sz e.g. loss of motivation

Question 7

Enlarged ventricles

Answer 7

. hollow spaces in the brain
. appear dark on brain scans
. tell us about lost brain mass

Question 8

AO3 for neural correlates as an explanation for Sz: RTS Suddath et al

Answer 8

P - RTS role of neural correlates as explanation for Sz from Suddath et al (1990)
E - used MRI scans investigate brain areas monozygotic twins - one twin was Sz
E - found that Sz twin generally more enlarged ventricles
L - suggests enlarged ventricles play role in determining likelihood of Sz developing

CA - biological reductionist

Question 9

Neural correlates: dopamine hypothesis (2m)

Answer 9

. brain chemical messengers (neurotransmitters) work differently in brain of Sz patient
. dopamine (DA) believed to be involved
. people with Sz release too much dopamine
. or have large amount D2 receptors on post synaptic neuron

Question 10

HYPERdopaminergia in the subcortex (2m)

Answer 10

. high dopamine activity in central brain areas
. e.g. Broca’s area (speech production)
. associated with auditory hallucinations
. high dopamine = high behaviour

Question 11

HYPOdopaminergia in the cortex (2m)

Answer 11

. low dopamine activity in prefrontal cortex (thinking/decisions)
. associated with negative symptoms e.g. avolition
. low dopamine = low motivation

Question 12

What does cortical hypodopaminergia lead to?

Answer 12

. cortical hypodopaminergia leads to subcortical hyperdopaminergia
. both high and low levels of dopamine activity
. in different brain regions
. involved in different symptoms of Sz

Question 13

AO3 for biological explanation of Schizophrenia: scientific methods

Answer 13

P - strength biological exp of Sz uses scientific methods
E - as theory based on objective and empirical techniques
E - e.g. gene mapping/brain scans - fMRI used identify specific genes (PCM1) or areas of brain linked to Sz (enlarged ventricles)
L - increases overall internal validity of biological exp of Sz - raising psych scientific status

Question 14

AO3 for biological explanation of Schizophrenia: biological determinism

Answer 14

P - biological exp of Sz criticised biological determinism
E - as theory states person controlled by internal factors - e.g. high dopamine activity (hyperdopamergia) in subcortex caused auditory hallucinations
E - so neglects role free will - choice ppl have - leave victims feeling like no control over Sz behaviour
L - also seen as unethical - can leave victim’s families feeling guilty as passed on gene that affected child - cannot be stopped - limits biological exp of Sz

Question 15

AO3 for biological explanation of Schizophrenia: practical applications

Answer 15

P - strength biological exp of Sz practical applications
E - as principles of theory - Sz caused by imbalance of dopamine activity - led to treatment drug therapies
E - e.g. typical and atypical antipsychotics - drugs effective in treating Sz - balancing levels dopamine in patient’s brain - so reducing symptoms of Sz e.g. hallucinations/delusions (+ve symptoms)
L - so biological exp of Sz important part applied psych - help treat people in real world - help live normal life

Question 16

AO3 for biological explanation of Schizophrenia: alternative - family dysfunction

Answer 16

P - alternative explanation development Sz - family dysfunction
E - argue Sz due to faulty communication patterns within family - e.g. schizophrenogenic mother - mother cold and creates family climate characterised by tension/secrecy
E - leads to distrust - later develops into paranoid delusions - rather than delusions being due to levels of dopamine/genes/neural correlates
L - so biological exp of Sz - not only exp needs be considered