Biological Explanation for Schizophrenia AO1

Question 1

Neural Correlates

Answer 1

• Patterns of structure or activity in the brain that occur in conjunction with an experience and may be implicated in the origins of that experience

Question 2

Dopamine

Answer 2

• A neurotransmitter with an excitatory effect
• Linked to sensations of pleasure
• Unusually high levels are associated with schizophrenia
• Unusually low levels are associated with Parkinson’s Disease

Question 3

Original DA hypothesis

Answer 3

• Antipsychotic drugs produce symptoms similar to Parkinsons disease (Low DA)
• Schuzophrenia caused by high DA levels in subcortex
• Explains some symptoms like speech poverty (connection to broca area disrupted)

Question 4

Updated DA hypothesis

Answer 4

• High DA in subcortex and low DA in cortex explains negative symptoms
• Da levels are affected by noth genetic vunerability and cjhildhood adolescence stress (Howes et al)

Question 5

Family studies

Answer 5

• Risk of schizophrenia increases with similarity to someone with condition

Question 6

Candidate genes

Answer 6

• Early reasearch believed one faulty gene could explain schizophrenia
• number of diff genes cause sxchizophrenia (polygenic)
• (Ripke et al), combined previous research from genome wide studies, 108 seperate genetic variations were associated with slightly increaed risk of schizophrenia
• aetiologically heterogeneous = different combos of genes are involved in the disorder

Question 7

The role of mutation

Answer 7

• Mutation of parental DNA
• caused by radiation, poison or viral infection
• evidence for mutations come from paternal age and risk of schizophrenia from 0.7% with fathers over 25 to 2% with fathers over 50