Biological Explanations

What are the 2 main biological explanations?

1. Genetics

2. Neurotransmitters ( Dopamine Hypothesis )

What did Gottesman and Shields (1972 + 1976) look into in regards to genetics and explain each one?

Family study = examine the similarity of a trait across members of the same family over generations

Twin study = compare the similarities and differences of identical twins (Mz) to fraternal (Dz) to isolate genetic influences

Adoption Study = look at indivduals who were separated from their biological at birth and raised by adopted families

What was the data collected from the twin study from Gottesman (1991)?

48% C.R in Mz

17% C.R in Dz

What does C.R mean ?

Concordance rate = probability that you are likely to inherit a disorder

What are the results of the adoption study?

Biological mother with schizophrenia = C.R for the adopted child is 6-7%

No mother with schizophrenia = 4% C.R

What is dopamine?

Neurotransmitter coming from the D2 receptor know to make you happy (reward)

What are the supports for the dopamine hypothesis?

1. Drug Trials

2. Post Mortem studies

3. PET scans

Explain drug trials as support for the dopamine hypothesis:

1. Cocaine and amphetamines takers experience hallucinations and delusions

2. L-dopa (artificial dopamine) used to treat parkinsons and patients reported H+D

However cocaine and amphetamines affect other neurotransmitters e.g serotonin

Explain post-mortem studies as support for the dopamine hypothesis

Schizophrenia patients had increased amounts of D2 receptors

However there was no significant difference in some cases

How do PET scans show support for the dopamine hypothesis?

PET scans shows locations of dopamine and those with schizophrenia had increased amounts of dopamine