Biological explanations

Question 1

what are concordance rates?

Answer 1

-likelihood that if one family member has schiz that other one will.

-in psych look at twin and adoption studies to assess concordance rates for schiz.

-look at the extent to which greater genetic similarity between family members is associated with likelihood of both family members level schiz.

Question 2

what are candidate genes?

Answer 2

-not a ‘schizophrenic gene’ but several individual genes involved with a risk of inheriting schiz (polygenic)

-diff studies identified diff candidate genes involved in schiz. so its aetiologically heterogeneous

Question 3

what does aetiologically heterogeneous mean?

Answer 3

different combinations of the genes can lead to the condition

Question 4

Ripke et al (2014) - candidate genes

Answer 4

-Found 108 diff genetic variations associated with increased risk of schiz. Some of these genes coded 4 functioning of neurotransmitters including dopamine.

-Be noted that having their genes doesn’t mean one will definitely develop schiz.

Question 5

Gottesman - running in families

Answer 5

as genetic similarity increases so does prob of sharing schiz:
-identical twins (48%)
-fraternal twins (17%)
-children (13%)
-siblings (9%)
-parents (6%)

Question 6

neural explanations

Answer 6

-development of schizophrenia is related to structural and functional brain abnormalities.

-includes activity of brain structures such as ventral striatum and neurotransmitters such as dopamine.

Question 7

what is dopamine

Answer 7

-dopamine is a neurotransmitter which operates in brain and is responsible for many of our feelings/behaviours

Question 8

what is the original dopamine hypothesis?

Answer 8

-original dopamine hyp stated patients with schiz have an oversensitivity to actions of dopamine.

-high numbers of D2; hypersensitive receptors; excess amounts of dopamine.

-thought they experienced hyperdopaminergic dopamine in subcortex (central brain).

-excess amount of dopamine receptors in Brocas area (speech production) -speech poverty + hallucinations.

Question 9

what does hyperdopaminergic mean?

Answer 9

too much dopamine

Question 10

what’s the more updated dopamine hypotheses?

Answer 10

-patients with schizophrenia may experience hypodopaminergic dopamine In cortex.

-Goldman-Rakic et al (2004) identified low levels of dopamine in prefrontal cortex which is responsible for decision making and may lead to -ve symptoms such as avolition.

Question 11

what does hypodopaminergic mean?

Answer 11

too little dopamine

Question 12

neural correlates

Answer 12

-ventral striatum linked to motivation and anticipated of reward.

-abnormalities in ventral striatum may be involved in the development of avolition

Question 13

Juckel et al (2006) - neural correlates

Answer 13

-found lower levels of activity in ventral striatum than in controls.

-also found -ve correlation between activity levels in ventral striatum and the severity of overall -ve symptoms.

Question 14

Allen et al (2007)- neural correlates

Answer 14

-scanned brains of individuals experiencing auditory hallucinations + compared to control group whilst they identified pre-recorded speech as theirs or that of others.

-lower activity levels found in superior temporal gyrus (STG) + anterior cingulate gyrus (ACG) of ppl experiencing auditory hallucinations.

-STG deals with speech processing

-ACG deals with error detection.

Question 15

Curran et al

Answer 15

Amphetamines increase levels of dopamine and make schizophrenics symptoms work but also produce schizophrenic symptoms in ppl who aren’t diagnosed.

Question 16

Tauscher et al

Answer 16

Antipsychotic drugs reduce dopamine activity and therefore improve schizophrenic symptoms.