title: Metabolite signature for diagnosing major depressive disorder in peripheral blood mononuclear cells.
abstract: BACKGROUND
  Major depressive disorder (MDD) is a serious debilitating psychiatric disorder. However, the molecular mechanisms of MDD remain largely unknown, and no objective laboratory-based tests are available to diagnose this disorder.
  
  
  METHODS
  A gas chromatography-mass spectrometry (GC-MS) based metabolomic approach was used to compare peripheral blood mononuclear cells (PBMC) metabolic profiling of 50 first onset drug-naïve MDD subjects and 50 healthy controls (training samples), to identify potential metabolite biomarkers for MDD. An independent sample cohort including 58 MDD patients, 40 schizophrenia (SCZ) patients and 56 healthy controls (test samples) was used to validate diagnostic generalizability and specificity of identified biomarkers.
  
  
  RESULTS
  17 PBMC metabolites responsible for discriminating MDD group from healthy control group were identified. These metabolites were mainly involved in disturbances of energy and neurotransmitter metabolism. This PBMC metabolite signature could effectively discriminate MDD subjects from the healthy controls with an AUC of 0.926 in training samples and 0.870 in test samples. Moreover, this metabolite signature enabled distinguishing MDD subjects from schizophrenia subjects with an AUC of 0.899.
  
  
  CONCLUSIONS
  This study was limited by potential confounding effects of different drug treatments in some MDD and schizophrenia subjects, and lack of animal studies to further validate the identified metabolite pathways in MDD.
  
  
  CONCLUSIONS
  These findings suggest that early disturbances of PBMC energy and neurotransmitter metabolism may be associated with the onset of MDD. This PBMC metabolite signature may facilitate development of a laboratory-based diagnostic test for MDD.
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Neurobiology, Chongqing, China; Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zheng
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Neurobiology, Chongqing, China; Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Fang
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Neurobiology, Chongqing, China; Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing, China.
authors.forename: Xue-Jiao
authors.initials: XJ
authors.lastname: Xu
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Neurobiology, Chongqing, China; Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing, China.
authors.forename: Mei-Ling
authors.initials: ML
authors.lastname: Liu
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Neurobiology, Chongqing, China; Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing, China.
authors.forename: Xiangyu
authors.initials: X
authors.lastname: Du
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Neurobiology, Chongqing, China; Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing, China.
authors.forename: Xiaotong
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Neurobiology, Chongqing, China; Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing, China.
authors.forename: Haiyang
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Neurobiology, Chongqing, China; Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing, China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Neurobiology, Chongqing, China; Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing, China. Electronic address: xiepeng@cqmu.edu.cn.
authors.forename: Peng
authors.initials: P
authors.lastname: Xie
mesh_terms: D000328:Adult; D000818:Animals; D015415:Biomarkers / Q000097:blood*; D003865:Major Depressive Disorder / Q000097:blood* / Q000175:diagnosis*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008297:Male; D055432:Metabolomics / Q000379:methods*; D018377:Neurotransmitter Agents / Q000378:metabolism; D012559:Schizophrenia / Q000097:blood / Q000175:diagnosis; D012680:Sensitivity and Specificity; D024502:alpha-Tocopherol / Q000378:metabolism
chemical_list: D015415:Biomarkers; D018377:Neurotransmitter Agents; D024502:alpha-Tocopherol