Objective To identify distinct subgroups of military personnel from Paracel Islands based on mental status for providing basis to intervention measures.Methods 174 enlisted military personnel were interviewed by symptom checklist-90 (SCL-90).The factor scores of SCL-90 were compared with army man norm and control group,then the cluster analysis was conducted.Results Interpersonal sensitivity,phobic and psychoticism of military personnel on Paracel Islands((1.65±0.56),(1.24±0.33),(1.44±0.46)) scored lower than those of army man norm (P＜0.05).Interpersonal sensitivity of military personnel on Paracel Islands scored lower than those of control (P＜0.05),depression and anxiety of them had no difference to control (P＞0.05),while other factors of them scored higher than control.According to cluster analysis,174 military personnel were divided into three subgroups.The first subgroup with high scores for all nine SCL-90-R dimensions,the second cluster showed moderate scores and the third cluster had lowest scores.Statistically significant sociodemographic differences could be found between the cluster groups (P＜0.05).Conclusion The mental health status of military personnel stationed in Paracel Islands is good on the whole,and can be divided into three clusters with different demographic and service characteristics.

The clinical data of 5 patients with autoimmune encephalitis admitted to the psychiatric department of the 904th Hospital of the Joint Logistics Service Force from January 2016 to June 2020 were retrospectively analyzed. Among 5 patients, 4 had stress psychological events within one month before the onset, and 3 had precursor symptoms such as fever and vomiting. They were all characterized by rapid progress of atypical mental and behavioral abnormalities and cognitive impairment. In terms of neurological symptoms, 1 case had faciobrachial dystonic seizures (FBDS), 3 cases had seizures, 2 cases had involuntary movement, and 4 cases had autonomic dysfunction, including central hypopnea, arrhythmia, blood pressure instability and paroxysmal facial flushing. Most neurological symptoms occur within 1 month of the onset. MRI revealed abnormalities in cerebral cortex, thalamus, temporal lobe and insular lobe in 4 cases; EEG demonstrated bilateral short-range medium amplitude θ wave in 2 cases. Abnormal cerebrospinal fluid (CSF) pressure was detected in 4 cases and 2 cases had abnormal cell number CSF. Three patients had positive anti-N-methyl-D-aspartate receptor (NMDAR) antibody, one patient had positive anti-LGI1 antibody, and one patient had positive anti-γ-aminobutyric acid B receptor (GABA BR) antibody. One case was discharged automatically, the remaining 4 patients were treated with glucocorticoid or combined with gamma globulin and cyclophosphamide, antiepileptic drugs, antipsychotic drugs and other symptomatic treatment, and their symptoms were relieved. Patients were followed up for six months, there was slightly slow residual reaction in 2 cases and personality change in 1 case. Autoimmune encephalitis characterized by mental symptoms is likely to be misdiagnosed as mental disorders. Clinicians should identify symptoms different from mental disorders, taking into account of the possibility of autoimmune encephalitis, to make early diagnosis and treatment.