bioRxiv preprint doi: https://doi.org/10.1101/422345; this version posted September 20, 2018. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Twin Study of Early-Onset Major Depression Finds DNA Methylation Enrichment for Neurodevelopmental Genes Roxann Roberson-Nay1,2, Aaron R. Wolen4, Dana M. Lapato2,4, Eva E. Lancaster2,4, Bradley T. Webb1,2,4, Bradley Verhulst3, John M. Hettema1,2, Timothy P. YorK2,4 1. Virginia Commonwealth University, Department of Psychiatry, Richmond, VA. 2. Virginia Commonwealth University, Virginia Institute for Psychiatric and Behavioral Genetics, Richmond, VA. 3. Department of Psychology, Michigan State University, East Lansing, MI. 4. Virginia Commonwealth University, Department of Human and Molecular Genetics, Richmond, VA. Correspondence: Roxann Roberson-Nay, Ph.D., Virginia Commonwealth University, Depart- ment of Psychiatry, Virginia Institute for Psychiatric and Behavioral Genetics, P.O. Box 980489, Richmond, VA 23298, Fax (804) 828-0245, email: roxann.roberson-
[email protected]. bioRxiv preprint doi: https://doi.org/10.1101/422345; this version posted September 20, 2018. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Abstract Major depression (MD) is a debilitating mental health condition with peak prevalence occurring early in life. Genome-wide examination of DNA methylation (DNAm) offers an attractive comple- ment to studies of allelic risk given it can reflect the combined influence of genes and environment.