schizophrenia other biological explanation Flashcards
how many people with a first degree relative develop Sz
10%
how many people develop Sz with a second degree relative
2-6%
how many people with a MZ twin develop Sz
40-65%
what concordance rate with MZ did Gottesman and shields find
38%
why are genes linked to scizophrenia complex to understand
less than 1/3 of schizophrenics have family history
complex
no single gene has been identified
name 3 genes linked to Sz
22q11 - those with section missing show psychotic symptoms
fequency of Sz is 18%
DISC 1 - those with gene 1.4x more likely to develop
gene codes for GABA
Xq 23 region - gene varient
52% of schizophrenics have this
what are the strengths of the gentic explanation
+ gottesman and shields compared MZ and DZ twins, comparing blood groups finger prints and facial alikeness, MZ concordance 42%
DZ 9%
+ gottesman and shields replicates ither studies, reliable
+ heston comapred children adopted at birth because mother had Sz with healthy children, 10% developed SZ
+ in a review of 14 studies Dahoun concluded the DISC 1 gene is associated with presynaptic dopamine dysregulation
what are the weaknesses of the genetic explanation
- reductionist not focusing on the whole person
- gottesman and shields didnt find 100% concordance in MZ
- many people with Sz dont have family history and many with family hisorty dont have Sz
- Tiwaried mentioned other factors come from environment thay can affect mechanisms driven by genes
what is the diathesis stress model
genes create vulnerability for Sz rather than causing it
triggered by other biological or environmental factors