Decreased plasma neuropeptides in first-episode schizophrenia, bipolar disorder, major depressive disorder: associations with clinical symptoms and cognitive function

Hua Yu; Peiyan Ni; Liansheng Zhao; Yang Tian; Mingli Li; Xiaojing Li; Wei Wei; Jinxue Wei; Wei Deng; Xiangdong Du; Qiang Wang; Wanjun Guo; Xiaohong Ma; Jeremy Coid; Tao Li

doi:10.3389/fpsyt.2023.1180720

Decreased plasma neuropeptides in first-episode schizophrenia, bipolar disorder, major depressive disorder: associations with clinical symptoms and cognitive function

Front Psychiatry. 2023 May 19:14:1180720. doi: 10.3389/fpsyt.2023.1180720. eCollection 2023.

Authors

Hua Yu^{1

2}, Peiyan Ni³, Liansheng Zhao³, Yang Tian³, Mingli Li³, Xiaojing Li¹, Wei Wei¹, Jinxue Wei³, Wei Deng¹, Xiangdong Du⁴, Qiang Wang³, Wanjun Guo¹, Xiaohong Ma³, Jeremy Coid³, Tao Li¹

Affiliations

¹ Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
² NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
³ The Psychiatric Laboratory and Mental Health Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
⁴ Suzhou Psychiatry Hospital, Affiliated Guangji Hospital of Soochow University, Suzhou, Jiangsu, China.

Abstract

Background: There is an urgent need to identify differentiating and disease-monitoring biomarkers of schizophrenia, bipolar disorders (BD), and major depressive disorders (MDD) to improve treatment and management.

Methods: We recruited 54 first-episode schizophrenia (FES) patients, 52 BD patients, 35 MDD patients, and 54 healthy controls from inpatient and outpatient clinics. α-Melanocyte Stimulating Hormone (α-MSH), β-endorphin, neurotensin, orexin-A, oxytocin, and substance P were investigated using quantitative multiplex assay method. Psychotic symptoms were measured using the Brief Psychiatric Rating Scale (BPRS) and Positive and Negative Syndrome Scale (PANSS), manic symptoms using the Young Mania Rating Scale (YMRS), and depressive symptoms using 17 item-Hamilton Depression Rating Scale (HAMD). We additionally measured cognitive function by using a battery of tests given to all participants.

Results: α-MSH, neurotensin, orexin-A, oxytocin, and substance P were decreased in the three patient groups compared with controls. Neurotensin outperformed all biomarkers in differentiating patient groups from controls. There were no significant differences for 6 neuropeptides in their ability to differentiate between the three patient groups. Higher neurotensin was associated with better executive function across the entire sample. Lower oxytocin and higher substance p were associated with more psychotic symptoms in FES and BD groups. β-endorphin was associated with early morning wakening symptom in all three patient groups.

Conclusion: Our research shows decreased circulating neuropeptides have the potential to differentiate severe mental illnesses from controls. These neuropeptides are promising treatment targets for improving clinical symptoms and cognitive function in FES, BD, and MDD.

Keywords: bipolar disorder; disease monitoring; major depressive disorder; neuropeptide; schizophrenia.