Association between visual impairment and psychosis: A longitudinal study and nested case-control study of adults

Druggable genome-wide Mendelian randomization for identifying the role of integrated stress response in therapeutic targets of bipolar disorder

For bipolar disorder (BD), the inconsistency of treatment guidelines and the long phases of pharmacological adjustment remain major challenges. BD is known to be comorbid with many medical and psychiatric conditions and they may share inflammatory and stress-related aetiologies, which could give rise to this association. The integrated stress response (ISR) responds to various stress conditions that lead to alterations in cellular homeostasis. However, as a causative mechanism underlying cognitive deficits and neurodegeneration in a broad range of brain disorders, the impact of ISR on BD is understudied. Mendelian randomization has been widely used to repurpose licensed drugs and discover novel therapeutic targets. Thus, we aimed to identify novel therapeutic targets for BD and analyze their pathophysiological mechanisms, using the summary data-based Mendelian Randomization (SMR) and Bayesian colocalization (COLOC) methods to integrate the summary-level data of the GWAS on BD and the expression quantitative trait locus (eQTL) study in blood. We utilized the GWAS data including 41,917 BD cases and 371,549 controls from the Psychiatric Genomics Consortium and the eQTL data from 31,684 participants of predominantly European ancestry from the eQTLGen consortium. The SMR analysis identified the EIF2B5 gene that was associated with BD due to no linkage but pleiotropy or causality. The COLOC analysis strongly suggested that EIF2B5 and the trait of BD were affected by shared causal variants, and thus were colocalized. Utilizing data in EpiGraphDB we find other putative causal BD genes (EIF2AK4 and GSK3B) to prioritize potential alternative drug targets.

Retina as a potential biomarker in schizophrenia spectrum disorders: a systematic review and meta-analysis of optical coherence tomography and electroretinography

INTRODUCTION

Abnormal findings on optical coherence tomography (OCT) and electroretinography (ERG) have been reported in participants with schizophrenia spectrum disorders (SSDs). This study aims to reveal the pooled standard mean difference (SMD) in retinal parameters on OCT and ERG among participants with SSDs and healthy controls and their association with demographic characteristics, clinical symptoms, smoking, diabetes mellitus, and hypertension.

METHODS

Using PubMed, Scopus, Web of Science, and PSYNDEX, we searched the literature from inception to March 31, 2023, using specific search terms. This study was registered with PROSPERO (CRD4202235795) and conducted according to PRISMA 2020.

RESULTS

We included 65 studies in the systematic review and 44 in the meta-analysis. Participants with SSDs showed thinning of the peripapillary retinal nerve fiber layer (pRNFL), macular ganglion cell layer- inner plexiform cell layer, and retinal thickness in all other segments of the macula. A meta-analysis of studies that excluded SSD participants with diabetes and hypertension showed no change in results, except for pRNFL inferior and nasal thickness. Furthermore, a significant difference was found in the pooled SMD of pRNFL temporal thickness between the left and right eyes. Meta-regression analysis revealed an association between retinal thinning and duration of illness, positive and negative symptoms. In OCT angiography, no differences were found in the foveal avascular zone and superficial layer foveal vessel density between SSD participants and controls. In flash ERG, the meta-analysis showed reduced amplitude of both a- and b-waves under photopic and scotopic conditions in SSD participants. Furthermore, the latency of photopic a-wave was significantly shorter in SSD participants in comparison with HCs.

DISCUSSION

Considering the prior report of retinal thinning in unaffected first-degree relatives and the results of the meta-analysis, the findings suggest that retinal changes in SSDs have both trait and state aspects. Future longitudinal multimodal retinal imaging studies are needed to clarify the pathophysiological mechanisms of these changes and to clarify their utility in individual patient monitoring efforts.

Relationship between Loneliness and Mild Behavioral Impairment: Validation of the Japanese Version of the MBI Checklist and a Cross-Sectional Study

Background

Mild behavioral impairment (MBI) and loneliness are associated with cognitive decline and an increased risk of dementia.

Objective

Our aim was to examine the validity of the Japanese version of the MBI checklist (MBI-C) and investigate the relationship between loneliness and MBI.

Methods

The participants in this cross-sectional study included 5 cognitively normal persons and 75 persons with mild cognitive impairment. MBI-C and the revised University of California at Los Angeles loneliness scale (LS) were used to assess MBI and loneliness, respectively. Diagnostic performance of MBI-C was examined using receiver operating characteristic analysis. The relationship between MBI-C and LS was examined using multiple linear regression in 67 subjects who were assessed with both scales, with MBI-C total or domain score as the dependent variable and LS as the independent variable, adjusted for age, gender, living situation, presence of visual and hearing impairment, and Mini-Mental State Examination score.

Results

Per the Youden index, in this mostly MCI sample, the optimal MBI-C cut-off score was 5.5 with sensitivity 0.917 and specificity 0.949. In multiple linear regression analysis, LS score was detected as a significant predictor of MBI-C total scores, and MBI-C decreased motivation, affective dysregulation, and abnormal thought and perception scores.

Conclusions

The caregiver-rated Japanese MBI-C has excellent diagnostic performance. Loneliness is associated with a greater MBI burden, especially in the decreased motivation, affective dysregulation, and abnormal thought and perception domains. Interventions for loneliness in older people may have the potential to improve MBI.