Table II. Epigenome-wide association studies in post-traumatic stress disorder. OEF/OIF-Operation Enduring/Iraqi Freedom; MRS- Marine Resiliency Study; PRISMO- Prospective Research in Stress-Related Military Operations; VA-M- Veterans Affairs’ Mental Illness Research, Education and Clinical Centers; VA-NCPTSD- National Center for PTSD; WTC- World Trade Center 9/11 First Responders study.

Study	Sample Size	Cohort	Significant CpG site(s)	Gene	P value	Highlights
Hammamieh et al, 2017	Training set: N=99 Test set: N=60 Merged: N=159	OEF/OIF Male Amer-ican military veterans	5578 differential-ly methylated CpG islands	3662 DMGs 3339 DMGs	<5.00E-2 (unadjusted)
Kuan et al, 2017	N=473	WTC	cg05693864 cg06182923 cg08696494 cg25664402 cg05569176 cg09370982 cg07654569	Zinc finger DHHC-type containing 11 (ZDHHC11) CUB and sushi multiple domains 2 (CSMD2) Collagen type IX alpha 3 chain (COL9A3) Intergenic Programed cell death 6 Interacting protein (PDCD6IP) TBC1 domain family member 24 (TBC1D24) Family with sequence similarity 164, member A (FAM164A)	1.73E-06 4.73E-05 5.39E-05 5.80E-05 7.82E-05 8.97E-05 9.91E-05
Ratanatharathorn et al, 2017	N=147	Four military cohorts (MRS, PRISMO, VA-M, and VA-NCPTSD) Three civilian cohorts (DNHS, GTP, and WTC)		Proposed – Consortium Study Description		Planned meta- analysis
Uddin et al, 2018	N=545	Civilian trauma ex-posed cohorts	cg23637605 cg19577098	Neuregulin 1 (NRG1) Hepatocyte growth factor-regulated tyrosine ki-nase substrate (HGS)	4.66E-08 1.47E-07	Meta- analysis