Biological explanation to SZ

Question 1

What did Gottesman find abt the relationship between biology and SZ

Answer 1

1991
Findings have shown that the greater the degree of genetic relatedness, the greater the risk of developing SZ

Question 2

What did Gottesman and Shields 1962 find w twin studies

Answer 2

Concordance rate for SZ in monozygotic twins was 48% compared to 17% for diozygotic twins
Suggested that SZ is inherited through shared genes
Joseph 2004 showed concordance rate of 40.4% MZ and 7.4% DZ

Question 3

What abt Heston’s 1966 adoption studies

Answer 3

Compared 47 adopted children whose biological mother had SZ with a control group of adopted children with no history of SZ in their biological family
None of the control group was diagnosed w SZ
16% of offspring of mothers with SZ were diagnosed

Tienari et al 2000
11% of 164 adoptees whose mothers have SZ

Question 4

What is SZ thought to be

Answer 4

Polygenic

Question 5

Ripke et al 2014’s study combining data from a genome wide study of SZ found what

Answer 5

37k patients were compared to 113k controls
108 separate genetic variations were associated with an increased risk of SZ

Question 6

What is the dopamine hypothesis

Answer 6

Excess of neurotransmitter dopamine has been implicated in the symptoms of SZ
Hyperdopaminergia (too much) in the subcortex
Hypodopaminergie (too little) in the cortex

Question 7

What might hyperdopaminergia effect

Answer 7

Poverty of speech
Experience of auditory hallucinations

Question 8

What does hypodopaminergia effect

Answer 8

-ve symptoms of SZ
Thinking
Decision-making

Question 9

What is evidence for dopamine

Answer 9

Drugs
nah im being serious it is
Amphetamines - stimulates nerve cells containing dopamine causing the synapse to be ‘flooded’, large does can cause hallucinations and delusions
Crack cocaine, a personal fav - increases the levels of dopamine in the brain and can cause the +ve symptoms of SZ and exaggerate them in people who already have SZ
Antipsychotic drugs - blocks activity of dopamine in brain by reducing stimulation of the dopamine system, eliminates hallucinations and delusions. By alleviating many of the symptoms of SZ, antipsychotic drugs strengthen the case for dopamine being a significant contributory factor

Question 10

What are the neural correlations of SZ -ve symptoms

Answer 10

Activity in the ventral striatum has been linked to the development of avolition (loss of motivation)
The ventral striatum are believed to be particularly involved in the anticipation of reward for certain actions
Juckel et al 2006 lower levels compared to controls
-ve correlation between activity levels in the ventral striatum and the severity of overall -ve systems

Question 11

What are neural correlations of SZ +ve symptoms

Answer 11

Reduced activity in the superior temporal gyrus and anterior cingulate gyrus have been linked to the development of auditory hallucinations
Patients experiencing auditory hallucinations showed lower activation levels in these areas than controls
Therefore reduced activity in these areas of the brain is neural correlate of auditory hallucinations

Question 12

What abt ventricles

Answer 12

yup thats the q

People w SZ have abnormally large ventricles in the brain
Ventricles are fluid filled cavities
This means that the brains of people w SZ are lighting than normal