biological explanations of schizophrenia Flashcards
Kendlers family study
Kendler 1985 found first-degree relatives of a diagnosed person are 18x more likely to get SZ than general population
Gottesman family study
Gottesman 1991 - large scale family study examined the % risk for different relatives of a diagnosis - MZ twins = 48%, DZ twins = 17%, children = 13%, siblings 9%, grandchildren 5%
Parmas study
Parmas 1993 - found 16% of children with SZ mothers developed the disorders themselves whilst only 2% of children with non SZ mothers did
Gottesman and shields twin study
Gottesman and Shields 1976 - reviewed 5 twin studies found CR for MZ twins with severe, chronic SZ varied between 75%-91% = genetics play a role in serious cases
Janicak twin study
Janicak 2004 - found MZ=48% and DZ=17%
Kety and Ingraham adoption study
Kety and Ingraham 1992 found prevalence rates of SZ were 10x higher among genetic relatives compared to adoptive relatives of SZ = genes play a greater role than environmental factors
what does polygenic mean in terms of SZ
SZ may have multiple genes that are expressed together in the development of the disorder
Ripke study evidence for candidate genes
Ripke 2014 - conducted meta-analysis combining data from genome-wide research of SZ - genetic makeup of 37,000 SZ patients and 113,000 controls = found 108 seperate genetic variations
gurling study for candidate genes
Gurling 2006 - used a gene-mapping technique that found the PCMI genes was implicated with vulnerability to SZ
benzel study for candidate genes
Benzel 2007 - also used gene mapping and found evidence suggesting that the NRG3 gene variant interacted with other gene variant
limitation of twin studies
don’t consider the influence of a shared environment or social-psychological differences + if genes were only factor than MZ would be 100%
