Major depressive disorder (MDD) is diagnosed by subjective clinical evaluation,leading to underdiagnosis and misdiagnosis.Statedependentbiomarkers for MDD would be efficacious in improving diagnostic accuracy,but are not yet available.Stress-inducedhippocampal apoptosis has been previously reported in MDD and G200902 has been shown to be protective against apoptosis,butG200902s mechanistic role in MDD,if any,remains unknown.