Biological explanations

Question 1

genetic association

Answer 1

• tends to run in families genetically related
• more likely to develop if a family member has sz

Question 2

family studies

Answer 2

• more common in bio relatives of a someone with schiz
• closer relatedness, the greater the risk
• gottesman: kids with; two sz parents = 46%, one sz parent = 13%, sz sibling = 9%

Question 3

twin studies

Answer 3

• joseph (2004):
• MZ: 40.4%
• DZ: 7.4%

Question 4

adoption studies

Answer 4

• tiernari (2000)
• 6.7% adoptees w/ a mother w/ sz, had sz
• 2% of adoptees w/ non-sz mothers

Question 5

dopamine (D) hypothesis

Answer 5

• excess D in certain brain regions = +ve symptoms of SZ
• more D2 receptors = more D binds = more neurons fire

Question 6

drugs effecting dopaminergic activity

Answer 6

• amphetamine - D agonist, increases D in the synapse
• cause characteristic episodes of schizophrenia
• antipsychotics: block dopamine in the brain, alleviate positive symptoms

Question 7

pre-frontal cortex

Answer 7

• involved in executive control
• impaired in SZ patients
• results in cognitive symptoms of SZ

Question 8

the hippocampus

Answer 8

• anatomical changes in SZ patients
• deficits correlate with WM impairments and central cognitive impairments
• may influence levels of dopamine release

Question 9

grey and white matter

Answer 9

• SZ patients have reduced vol of grey matter and enlarged brain cavities filled with cerebrospinal fluid
• white: reduced myelin in white matter pathways

Question 10

Biological Explanation strengths

Answer 10

RESEARCH SUPPORT
- joseph: MZ ccd rates of 40.4% - shows strong genetic component supports SZ inherited
EEFECTIVE DRUG TREATMENTS / REAL WORLD APPS
- leucht. 212 studies: antipsychotics more effective than placebos
- supports dopamine hypothesis if drugs blocking dopamine reduce SZ symptoms
SUPPORT FOR INFLUENCE OF GREY MATTER
- vita et al. SZ patients showed higher reduction in grey cortical matter compared to healthy controls - shows it causes SZ, but don’t know is symptoms a result or cause of grey matter so cannot establish C+E

Question 11

Biological Explanations limitations

Answer 11

CRITICISING EVIDENCE
- Noll: 1/3 of SZ patients don’t respond to antipsychotics and some show +ve symptoms despite having normal levels of dopamine
- dopamine not the sole cause, other neurotransmitters involved