Biological explanations

Question 1

The dopamine hypothesis

Answer 1

• claims that an excess of dopamine causes positive symptoms of schiz
• Abnormally high D2 receptors in schiz cause more dopamine binding and more excitatory neurons

Question 2

Revised dopamine hypothesis

Answer 2

The negative and positive symptoms are thought to arise from a deficit of dopamine in areas of the prefrontal cortex

Question 3

Genetic explanations

Answer 3

Gottesman
- demonstrates a positive correlation between increased genetic similarity of family members and their increased risk of shiz

Monozygotic = 48%
dizygotic = 17%
siblings = 9%
parents = 6%

Strongly suggests a genetic basis of schiz

Question 4

Neural correlates

Answer 4

Related to structure of brain and functional brain abnormalities
Amygdala - smaller in shiz so can link to loss of emotion
Basal ganglia = larger in shiz so can cause motor dysfunction

Question 5

Strengths

Answer 5

Research support - genetics

Tienari - 164 finland adoptees had bio mothers with shiz
- 11 also received diagnosis of shiz compared to 4 in control group

Amphetamines - dopamine
- A increase levels of dopamine in the synapse
- large doses cause shiz

Question 6

Limitations

Answer 6

Reductionist - bio
- Reduces it to Purley biological without considering external factors

issues with causation
- just coz dopamine and schiz have correlation doesnt mean that dopamine causes shiz

methodological issues
- twin studies subject to reesearcher bias some researchers may say its schiz whilst others may say its not