title: Peripheral blood nerve growth factor levels in major psychiatric disorders.
abstract: Nerve growth factor (NGF) plays crucial roles in promoting neural growth and survival, and mediating synaptic and morphological plasticity. Several studies investigated the correlation between peripheral NGF levels and major psychiatric disorders, including schizophrenia (SCZ), major depressive disorder (MDD) and bipolar disorder (BPD); however, the findings were inconsistent. This meta-analysis sought to investigate blood NGF levels in patients with psychiatric disorders compared with healthy subjects and examined potential effects of blood fraction, medication and disease status. A total of 21 eligible studies, encompassing 1342 patients suffering from psychiatric disorders and 1225 healthy subjects, were enrolled in the present meta-analysis. No obvious publication bias was observed either for SCZ, MDD or BPD by the Begg's test (P > 0.05). Random-effects meta-analysis showed that SCZ (Z = 2.14, P = 0.033, SMD = -1.08, 95% CI = -2.07 to -0.09) and MDD (Z = 2.57, P = 0.010, SMD = -0.61, 95% CI = -1.08 to -0.14) patients had significantly reduced NGF levels, compared with healthy controls. Notably, this decrease was enhanced in un-medicated patients of SCZ (P = 0.004) and medicated or chronic patients of MDD (P < 0.001). No significant difference of NGF levels was observed between BPD patients and controls (P > 0.05). These results supported an association between the reduction of NGF levels and psychiatric disorders. It remains unclear whether the change of NGF levels is a prerequisite for its function in psychiatric disorders development or merely an epiphenomenon unrelated to the pathophysiologic mechanisms.
authors.affiliation: School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China. Electronic address: shuquan_rao@163.com.
authors.forename: Shuquan
authors.initials: S
authors.lastname: Rao
authors.affiliation: Araba University Hospital, Bioaraba Research Institute, Vitoria, Spain; Biomedical Research Networking Centre in Mental Health (CIBERSAM), Madrid, Spain; National Distance Education University (UNED), Vitoria, Spain.
authors.forename: Mónica
authors.initials: M
authors.lastname: Martínez-Cengotitabengoa
authors.affiliation: Department of Fundamental Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Yao
authors.affiliation: School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China.
authors.forename: Zhiyun
authors.initials: Z
authors.lastname: Guo
authors.affiliation: National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 10005, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Xu
authors.affiliation: School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China.
authors.forename: Suiyan
authors.initials: S
authors.lastname: Li
authors.affiliation: School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China.
authors.forename: Xianli
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Wuxi Mental Health Center, Nanjing Medical University, Wuxi, 214151, China.
authors.forename: Fuquan
authors.initials: F
authors.lastname: Zhang
mesh_terms: D015415:Biomarkers / Q000097:blood; D006801:Humans; D001523:Mental Disorders / Q000097:blood*; D020932:Nerve Growth Factor / Q000097:blood*
chemical_list: D015415:Biomarkers; C502240:NGF protein, human; D020932:Nerve Growth Factor
keywords: Meta-analysis; NGF; Peripheral levels; Psychiatric disorders