DNA methylation biomarkers of post-partum depression risk

A method for determining post-partum depression (PPD) therapy for a patient having or at risk of having PPD, comprising:

• a) measuring DNA methylation levels of a panel of biomarker loci comprising HP1BP3 loci and TTC9B loci, and optionally PABPCIL loci and/or OXTR loci
• wherein the HP1BP3 loci is located at chr1:20986708-20986650 of human genome build hg 18, the TTC9B loci is located at chr19:45416573 of human genome build hg 18, the PABPCIL loci is located at chr20:42971786-42971857 of human genome build hg 18, and the OXTR loci is located at chr3:8785134-8785171 of human genome build hg 18, and
• wherein the DNA methylation levels of HP1BP3 loci are measured by amplification using a primer comprising any of SEQ ID NOs:
• 8-12 and the DNA methylation levels of TTC9B loci are measured by amplification using a primer comprising any of SEQ ID NOs:
• 13-17;
• and
• b) using the relative DNA methylation levels of at least the HP1BP3 loci and the TTC9B loci of the patient compared to a control sample from a patient not having or at risk of having PPD, to determine the PPD therapy.

A method for determining an increased risk or likelihood of developing post-partum depression (PPD) in a human patient comprising:

• a) estimating a ratio of monocytes to non-monocytes in a sample collected from the patient;
• b) measuring DNA methylation levels of a panel of biomarker loci comprising HP1BP3 loci and TTC9B loci, in the sample collected from the patient by amplification using one or more primers comprising SEQ ID NOs:
• 8-17, wherein the HP1BP3 loci is located at chr1:20986708-20986650 of human genome build hg 18 and the TTC9B loci is located at chr19:45416573 of human genome build hg 18;
• and
• c) using a linear model that utilizes the DNA methylation level of HP1BP3, TTC9B and the ratio of monocytes:non-monocytes to determine that the patient is at increased risk or likelihood of developing PPD.