AUTHOR=Jiang Wenhao , Ding Shihang , Xu Cong , Ke Huihuang , Bo Hongjian , Zhao Tiejun , Ma Lin , Li Haifeng TITLE=Discovering the neuronal dynamics in major depressive disorder using Hidden Markov Model JOURNAL=Frontiers in Human Neuroscience VOLUME=Volume 17 - 2023 YEAR=2023 URL=https://www.frontiersin.org/journals/human-neuroscience/articles/10.3389/fnhum.2023.1197613 DOI=10.3389/fnhum.2023.1197613 ISSN=1662-5161 ABSTRACT=Major Depressive Disorder (MDD) is a leading cause of worldwide disability, and standard clinical treatments have limitations due to the absence of neurological evidence. Electroencephalography (EEG) monitoring is an effective method for recording neural activities and can provide eletroneurophysiological evidence of MDD. In this work, we proposed a probabilistic graphical model for neural dynamics decoding on MDD patients and healthy controls (HC), utilizing the Hidden Markov Model with Multivariate Autoregressive observation (HMM-MAR). We testified the model on the MODMA dataset, which contains resting-state and task-state EEG data from 53 participants, including 24 individuals with MDD and 29 HC. The experimental results suggest that the state time courses generated by the proposed model could regress the Patient Health Questionnaire-9 (PHQ-9) score of the participants and reveal differences between the MDD and HC groups. Meanwhile, the Markov property was observed in the neuronal dynamics of participants presented with sad face stimuli. Coherence analysis and power spectrum estimation demonstrate consistent results with the previous studies on MDD. In conclusion, the proposed HMM-MAR model has revealed its potential capability to capture the neuronal dynamics from EEG signals and interpret brain disease pathogenesis from the perspective of state transition.