Current viewpoints on DSM-5 in Japan

A nationwide web-based survey of factors associated with depressive symptoms among Japanese workers

BACKGROUND

Precarious employment has affected mental health, and limited data are available on the association of low stress tolerance with depressive symptoms among Japanese workers.

AIMS

This study aimed to examine the relationship between stress tolerance and depressive symptoms among Japanese workers, including company employees, civil servants and self-employed persons in various industries.

METHODS

We conducted a nationwide cross-sectional study. From March 26 to April 6, 2020, we performed a web-based survey of Japanese workers. The questionnaire included questions on socioeconomic factors, the SOC scale that assesses stress tolerance, the CES-D, and the EQ-5D-5L. Multivariate regression analyses were performed to determine the factors associated with depressive symptoms.

RESULTS

We included 3,001 participants in the analysis. A high SOC score, adequate sleeping time and frequency of exercise were associated with higher depressive symptoms. Employment status and long working hours were not associated with depressive symptoms. Younger workers had lower SOC scores than older workers. An inverse correlation between the SOC score and CES-D score was found among Japanese workers.

CONCLUSIONS

Improving stress tolerance among younger workers is needed to prevent worsening mental health regardless of employment status for Japanese workers.

Psychological impact of the state of emergency over COVID-19 for non-permanent workers: a Nationwide follow-up study in Japan

Background

The outbreak of COVID-19 has caused mental health problems and increased unemployment due to the economic recession. This survey aimed to assess the psychological impact of the state of emergency. We estimated changes in mental health, quality of life, and unemployment experience for general workers during the first COVID-19 outbreak in Japan.

Methods

We conducted a nationwide follow-up study. During the periods of March 26 to April 6, 2020 and June 26 to July 2, 2020, we used the internet to survey general workers aged 15 to 59 years in Japan. The questionnaire items covered employment status and socioeconomic factors, and we used the Center for Epidemiologic Studies Depression Scale (CES-D) and EQ-5D-5L to assess depression and health-related quality of life (HR-QOL), respectively. The differences in outcomes of permanent and non-permanent workers were analyzed using propensity score analysis. A multiple linear regression analysis was performed to examine the relationship between unemployment and CES-D scores.

Results

We included 2351 subjects in the analysis. Changes in both CES-D scores and utility were not significantly different between the two groups. However, a significant difference was found regarding the rate of unemployment, which was associated with higher CES-D scores.

Conclusions

The present study demonstrated that the mental health of non-permanent workers was not negatively affected following the state of emergency due to COVID-19 in Japan. Unemployment is an important factor that influences the mental health of general workers.

Effects of Anserine/Carnosine Supplementation on Mild Cognitive Impairment with APOE4

Background: Oral supplementation of anserine/carnosine helps preserve cognitive functions in healthy older adults. Mild cognitive impairment (MCI) is a transition between cognitive-normal and dementia. Therefore, it needs to investigate whether anserine/carnosine supplementation (ACS) has effects on subjects with MCI. Methods: A randomized, double-blind, placebo-controlled 12-week trial was performed. Fifty-four subjects with MCI were randomized to an active group ingesting 750 mg of anserine and 250 mg of carnosine per day or a placebo (1:1). Evaluation of cognitive change was conducted utilizing a psychometric test battery. Results: The score improvement in the global Clinical Dementia Rating (gloCDR) was superior in the active group than placebo (p = 0.023). No beneficial effect in the active group was detected in the other psychometric tests including the Mini-Mental State Examination (MMSE), the Wechsler Memory Scale, and the Alzheimer’s Disease Assessment Scale (ADAS). When APOE4 positive (APOE4 (+)) or negative (APOE4 (-)) subjects were separately analyzed, beneficial change in the APOE4 (+) subjects was observed in MMSE (p = 0.025) as well as in gloCDR (p = 0.026). Conclusions: The present study might suggest that protective effects against cognitive decline in APOE4 (+) MCI subjects exist.

DNA methylation changes at SNCA intron 1 in patients with dementia with Lewy bodies

AIM

It is difficult to diagnose dementia with Lewy bodies (DLB) because it exhibits clinical and neuropathological overlap with both Alzheimer's disease and Parkinson's disease. The α-synuclein protein is a major component of Lewy bodies, and accumulation of α-synuclein aggregates causes synaptic dysfunction in DLB. Epigenetic changes at the synuclein alpha ( SNCA ) gene may be involved in DLB pathogenesis.

METHODS

We examined DNA methylation rates at 10 CpG sites located in intron 1 of SNCA and SNCA mRNA expression in peripheral leukocytes to compare DLB patients (n = 20; nine men, 11 women; age = 78.8 ± 7.7 years) with healthy controls (n = 20; eight men, 12 women; age = 77.0 ± 6.9 years).

RESULTS

The methylation rate at CpG 4 ( P  = 0.002) and the overall mean methylation rate at these sites (P < 0.001) were significantly lower in DLB patients than in healthy controls after Bonferroni correction. Although SNCA126 , a partial form of SNCA mRNA expression, was significantly increased in DLB ( P  = 0.017), there was no significant difference in total SNCA mRNA expression between DLB patients and healthy controls ( P  = 0.165). No correlation was observed between SCNA mRNA expression levels and blood DNA methylation rates in either DLB or healthy controls.

CONCLUSION

Our findings indicated that lower methylation rates may be a biomarker for DLB.