<p>The Mood Methylation Study (MMS) is an observational study designed to understand epigenetic mechanisms underlying major depression symptoms (MDD) using a co-twin control design. Twins enrolled in the MMS were monozygotic (MZ) twin pairs discordant on lifetime history of MDD. All twins were members of the Washington State Twin Registry (WSTR), a community-based twin registry consisting of over 10,000 twin pairs. Lifetime and current MDD diagnoses were determined using the Structured Clinical Interview for DSM-IV Research Version (SCID-4-RV). DNA methylation in blood monocytes was measured using the Infinium HumanMethylationEPIC BeadChip. Monocyte gene expression was quantified by paired end RNA-seq (50 PE). Zygosity of the twin pairs included in the MMS was self-reported and confirmed using the polymorphic SNPs included in the DNA methylation array.<br></p>

The Mood and Methylation Study (MMS)

Genome-wide profiling of DNA methylome and transcriptome in peripheral blood monocytes for major depression: A Monozygotic Discordant Twin Study

Study Design and Rationale for the Mood and Methylation Study: A Platform for Multi-Omics Investigation of Depression in Twins