The microbiota–gut–brain axis plays a critical role in the pathogenesis of major depressive disorder (MDD) and related subclinical symptoms. However, studies on the gut microbiota in MDD are inconsistent, and data on MDD's effects on sleep are lacking. This study aimed to analyze the gut microbiota composition and sleep quality of patients with MDD. We performed 16S rRNA sequencing of stool samples from 36 patients with MDD and 45 healthy controls (HC). Sleep quality was assessed using the Pittsburgh Sleep Quality Index, depressive severity with the Hamilton Depression Scale, and insomnia severity using the Insomnia Severity Index. Forty-eight microbiota targets showed significant differences between MDD and HC. In MDD, six microbiota targets were associated with the severity of depression, 11 with sleep quality, and 3 with sleep severity. At the genus level, Dorea was simultaneously related to depression and sleep quality, while Intestinibacter was more closely related to sleep problems. Coprococcus and Intestinibacter were associated with sleep quality independent of the severity of depression. In conclusion, the present findings enable a better understanding of the relationship between gut microbiota and MDD-related symptoms. Gut microbiota alterations may become potential biomarkers and/or treatment targets for sleep quality in MDD.

Objective: This research examines the intestinal‐associated flora of patients with depression compared with healthy volunteers to identify the characteristics and differences of flora associated with depression. It provides a theoretical basis for the prevention and treatment of depression through intestinal micro‐ecological regulation.Methods: We recruited 30 patients with depression to participate in the patient group (PG), and 30 volunteers were recruited for the healthy control group (HG) from the Beijing Hui‐long‐guan Hospital. Thereafter, the 16S rRNA high‐throughput sequencing method, using the Hamilton Depression Scale, was applied to analyze patient and healthy groups.Results: PG and HG microflora were different regarding phylum, Family, Genus, and Order. The results showed that Barnesiella was the dominant flora in depression patients, while Lachnospiraceae and Alloprevotella were the dominant bacteria in healthy participants. The proportion of Betaproteobateria (Proteobacteria), Alcaligenaceae (proinflammatory), Peptostreptococcaceae, Catenibacterium, Romboutsia, Sutterella, and Burkholderiales in the anxiety‐negative depressed group was significantly higher than in the anxiety‐positive group; and the proportion of Anaerostipes (inflammation) and Faecalibacterium (anti‐inflammatory) bacteria was significantly lower than that of patients with anxiety.Conclusion: Results showed there were differences in intestinal micro‐ecology between patients with depression and healthy volunteers. We found that the level of inflammation‐related bacteria in anxiety‐positive patients was lower than that in anxiety‐negative patients. These results enrich the knowledge of relationships between depression and intestinal flora and provide a theoretical basis for probiotics to assist in the treatment of depression.

Background: Recent studies have reported reductions in retinal nerve fiber layers (RNFL) in schizophrenia. Ciliary neurotrophic factor (CNTF) has shown protective effects on both the neurogenesis and retina. This study aimed at investigating retinal abnormalities and establishing their correlation with serum CNTF and cognitive impairments in schizophrenic Chinese patients. Methods: In total, 221 patients diagnosed with schizophrenia and 149 healthy controls were enrolled. Serum CNTF and clinical features of patients were investigated. Cognitive functions were evaluated with Repeatable Battery for the Assessment of Neuropsychology Status (RBANS). RNFL thickness and macular thickness (MT) of both eyes were measured with optical coherence tomography (OCT). T-tests and analysis of covariance were used to compare the variables between the patient and control groups, while multiple linear regression analysis was performed to determine the associations of RNFL thickness, CNTF and cognitive impairments. Results: RNFL was found thinner in patients than in healthy controls (right: 88.18 ± 25.84 µm vs.102.13 ± 14.32 µm, p = 0.001; left: 92.84 ± 13.54 µm vs.103.71 ± 11.94 µm, p < 0.001). CNTF was lower in the schizophrenia group (1755.45 ± 375.73 pg/ml vs. 1909.99 ± 368.08 pg/ml, p = 0.001). Decline in RNFL thickness was found correlated with course of illness and serum CNTF in patients (all p < 0.05). Similarly, cognitive functions such as immediate memory and visuospatial functions were also found correlated with decline in RNFL thickness. Conclusion: Decline in RNFL thickness was associated with cognitive impairments of schizophrenia and CNFT serum concentration. The possibility of reduction in RNFL thickness as a biomarker for schizophrenia needs to be further examined.

Suicide risk and auditory hallucinations are common in schizophrenia, but less is known about its associations. This cross-sectional study aimed to determine whether the presence and severity of auditory hallucinations were associated with current suicidal ideation or behavior (CSIB) among patients with schizophrenia. We interviewed 299 individuals with schizophrenia and acute symptoms and reviewed their medical records. Measurement included the Psychotic Symptom Rating Scale (PSYRATS-AH), the Calgary Depression Scale for Schizophrenia (CDSS), and the Positive and Negative Syndrome Scale. Logistic regression and path analysis were used. The CSIB prevalence was higher among patients with current auditory hallucination than those without (19.5% vs. 8.6%, crude odds ratio = 2.58, p = .009). Lifetime auditory hallucination experience (adjusted odds ratio [AOR] = 3.81; 95% CI: 1.45–10.05) or current auditory hallucination experience (AOR = 3.22; 95% CI: 1.25–8.28) can elevate the likelihood of CSIB while controlling for depressive symptoms and lifetime suicide-attempt history. Among those with auditory hallucinations, the emotional score of the PSYRATS-AH was positively associated with the CDSS score and there was a small indirect effect of the CDSS score on the association between the emotional domain score and CSIB (bias-corrected 95% CI, 0.02–0.20). In conclusion, the presence of auditory hallucinations was strongly associated with CSIB, independent of depressive symptoms and lifetime suicide attempts. Suicide risk assessment should consider auditory hallucination experience and patients’ appraisal of its emotional characteristics. Future cohort studies are necessary to provide more conclusive evidence for the mediating pathways between auditory hallucinations and CSIB.

Altered resting-state functional connectivity (rsFC) of the amygdala has been demonstrated to be implicated in schizophrenia neuronal pathophysiology. However, whether rsFC of amygdala subregions is differentially affected in schizophrenia remains unclear. This study compared the functional networks of each amygdala subdivision between healthy controls (HC) and patients with first-episode schizophrenia (FES). In total, 47 HC and 78 patients with FES underwent resting-state functional magnetic resonance imaging. The amygdala was divided into the following three subregions using the Juelich histological atlas: basolateral amygdala (BLA), centromedial amygdala (CMA), and superficial amygdala (SFA). The rsFC of the three amygdala subdivisions was computed and compared between the two groups. Significantly increased rsFC of the right CMA with the right postcentral gyrus and decreased rsFC of the right BLA with the left precentral gyrus were observed in the FES group compared with the HC group. Notably, the right BLA-left precentral gyrus connectivity was negatively correlated with positive symptoms and conceptual disorganization in patients with FES. In conclusion, this study found that patients with FES had abnormal functional connectivity in the amygdala subregions, and the altered rsFC was associated with positive symptoms. The present findings demonstrate the disruptive rsFC patterns of amygdala subregional-sensorimotor networks in FES and may provide new insights into the neuronal pathophysiology of FES.