Specificity of Psychiatric Polygenic Risk Scores and Their Effects on Associated Risk Phenotypes

• Type of Material: Article
• Authors: Amanda L Rodrigue, Harvard Medical School; Samuel R Mathias, Harvard Medical School; Emma E.M Knowles, Harvard Medical School; Josephine Mollon, Harvard Medical School; Laura Almasy, University of Pennsylvania; Laura Schultz, University of Pennsylvania; Jessica Turner, Georgia State University; Vince Calhoun, Emory University; David C Glahn, Harvard Medical School
• Language: English
• Date: 2023-07-01
• Publisher: Elsevier B.V
• Publication Version: Final Published Version
• Copyright Statement: © The Author(s) 2023
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.bpsgos.2022.05.008
• Title of Journal or Parent Work: Biological Psychiatry Global Open Science
• Volume: 3
• Issue: 3
• Start Page: 519
• End Page: 529
• Keywords: Trauma; MRI; Psychiatric genetics; Symptoms; Polygenic risk score; Cognition
• Research Categories: Computer Science; Psychology, Physiological; Biology, Neuroscience; Engineering, Electronics and Electrical; Biology, Genetics

Abstract

Background: Polygenic risk scores (PRSs) are indices of genetic liability for illness, but their clinical utility for predicting risk for a specific psychiatric disorder is limited. Genetic overlap among disorders and their effects on allied phenotypes may be a possible explanation, but this has been difficult to quantify given focus on singular disorders and/or allied phenotypes. Methods: We constructed PRSs for 5 psychiatric disorders (schizophrenia, bipolar disorder, major depressive disorder, autism spectrum disorder, attention-deficit/hyperactivity disorder) and 3 nonpsychiatric control traits (height, type II diabetes, irritable bowel disease) in the UK Biobank (N = 31,616) and quantified associations between PRSs and phenotypes allied with mental illness: behavioral (symptoms, cognition, trauma) and brain measures from magnetic resonance imaging. We then evaluated the extent of specificity among PRSs and their effects on these allied phenotypes. Results: Correlations among psychiatric PRSs replicated previous work, with overlap between schizophrenia and bipolar disorder, which was distinct from overlap between autism spectrum disorder and attention-deficit/hyperactivity disorder; overlap between psychiatric and control PRSs was minimal. There was, however, substantial overlap of PRS effects on allied phenotypes among psychiatric disorders and among psychiatric disorders and control traits, where the extent and pattern of overlap was phenotype specific. Conclusions: Results show that genetic distinctions between psychiatric disorders and between psychiatric disorders and control traits exist, but this does not extend to their effects on allied phenotypes. Although overlap can be informative, work is needed to construct PRSs that will function at the level of specificity needed for clinical application.