Polygenic risk in psychiatric illness is unrelated to brain volume or white matter microstructure

Prof Andrew McIntosh (Centre for Clinical Brain Sciences - Psychiatry) and colleagues have published a Nature paper using UK Biobank data to examine whether polygenic risk factors are related to structrual changes in the brain with major psychiatric illnesses such as schizophrenia or depression. Since brain structure and connectivity have been demonstrated to be inheritable traits, they wanted to know whether these were related to genetic risk factors associated with psychiatric illness. Using UKBiobank allowd them to use a single large quality-controlled dataset and, after examining MRI scans from 978 subjects for brain volume and 816 for white matter microstructure, they concluded that there was no evidence of shared genetic influence between these disorers and structural differences. This contradicts a number of studies which used smaller sample sizes.