SCHIZOPHRENIA-biological explanations Flashcards
what does evidence derive from for biological explanations?
family studies-genetics exp twin studies -genetics exp adoption studies -genetics exp biochemical explanations neuroanatomical explanations
studies supporting family studies?
kendler et al
main study KETY ET AL
studies supporting twin studies?
gottesman and shields
fischer
cardno et al
studies supporting adoption studies?
tienari et al x 2
wahlberg et al *
kety et al
studies supporting biochemical explanations?
falkai et al
wong et al
studies supporting neuroanatomical explanations?
wood et al weinberger buchsbaum flaum et al woodfruff et al castner et al
what are the bullet point for evidence from family studies? (3)
- 1st degree rels share 50% of genes and 2nd degree 25%
- family studies involve comparison of rates of schiz of relatives of diagnosed cases compared with relatives of controls
- evidence the closer bio relationship the greater risk of schiz developing
support for family studies kendler et al?
first degree rels of schiz = 18x more at risk compared to general population
opposition to kendler et al?
family studies conducted retrospectively when comparing cross section of people already diagnosed
what is bad about retrospective data?
unreliable as problems in memory and records= likely whereas prospective = more reliable as follow people over time b.f and after conditions
support for family studies main study?
kety et al
what happened in kety et al?
- high risk group= 207 offspring schizo mothers
- low risk=104 control children with healthy mothers
- children ages 10-18 matched age-gender-socio eco status-follow up testing on children conducted
- schizo diagnosed in 16.2% of high risk and only 1.9% of low risk group
positive of kety et al?
prospective study which follow development of schizo
matching of risk factors in children
negative & opposition of kety et al?
cant differentiate btw genetic and environmental influences as there is shared environment
another opposition of family studies?
many began before effective diagnostic symptoms so possible that there was variation of symptoms for original diagnosis of schiz
bullet point for evidence for twin studies? (4)
- compare difference in concordance rates of both twins mz and dz
- only mz have identical genes
- higher concordance rate in mz than dz
- mz twins reared apart can be used to distinguish effects of genetics and environ
what is concordance rates?
likelihood of both twins being affected with the disorder
what happened in support for twin studies gottesman and shields?
58% of twins who reared apart were concordant for schizophrenia
opposition of gottesman & shields?
even mz that rear apart share same womb envi b4 birth. The contrib of environ factors cant be entirely discounted