The COVID-19 pandemic immediately increased the suicide rate in Kobe, Japan, especially among populations without psychiatry and primary care physician visits: Interrupted time-series analysis using a population-based database (preprint)

Background Japan has one of the lowest numbers of deaths due to coronavirus disease (COVID-19). However, the annual number of suicides increased for the first time in 2020, after a downward trend since 2007. Objective This study aimed to identify high-risk populations and assess the impact of medical visits on suicide trends in Japan following the COVID-19 pandemic. Method This quasi-experimental study used a population-based database from Hyogo Prefecture between 2012 and 2022. Interrupted time-series analyses were used to identify immediate and slope changes in the monthly number of suicides during the exposure period (2020-2022) compared with the control (2012-2019). The analysis was stratified according to the status of psychiatric department and primary care physician visits. Results: A totalof 2181 cases were included. Two-thirds of the cases were male, with a median age of 54. Primary care physicians and psychiatric history were present in 69% and 40% of the patients, respectively. The level change was 4.46 (95%CI; 1.83, 7.09), 3.04 (95%CI; 1.45, 4.64), and 3.07 (95%CI; 0.60, 5.53), in the overall, no primary care physician visit, and no psychiatric visits groups, respectively, which were significant. The level change was not significant in the groups with primary care and psychiatric department visits, at 1.07 (95%CI; -0.84, 2.98) and 0.64 (95%CI; -1.05, 2.33), respectively. The slope changes were not significant in any group. Conclusion: This study suggests that visits to a medical institution may have helped prevent the rapid increase in suicides during the early stages of the COVID-19 pandemic.

Neutralizing Type I Interferon Autoantibodies in Japanese Patients With Severe COVID-19 (preprint)

PurposeAutoantibodies (aAbs) to type I interferons (IFNs) have been found in <1% of individuals under the age of 60 in the general population, with the prevalence increasing among those over 65. Neutralizing autoantibodies (naAbs) to type I IFNs have been found in at least 15% of patients with life-threatening COVID-19 pneumonia in several cohorts of primarily European descent. We aimed to define the prevalence of aAbs to IFN-α2 in 3,456 Japanese controls aged 20–91 and of aAbs and naAbs to IFN-α2 and IFN-ω in 627 Japanese COVID-19 patients aged 0–104, among whom were 170 critical, 235 severe, 112 moderate, 105 mild, and 5 asymptomatic infections.MethodsELISA and ISRE reporter assays were used to detect aAbs and naAbs using E. coli-produced IFNs.ResultsIn an uninfected general Japanese population aged 20–91, we found aAbs in 0.087% of individuals. naAbs to type I IFNs (IFN-α2 and/or IFN-ω, 100 pg/mL) were detected in 10.6% of patients with critical infections, 2.6% of patients with severe infections, and ≤1% of patients with asymptomatic to mild infections. They were higher in COVID-19 patients over 50 (5.8%) than in younger patients (0%) and higher in men (5.5%) than in women (1.1%). A significant but not strong correlation between aAbs and naAbs to IFN-α2 existed (r=-0.307, p-value<0.0001), stressing the importance of measuring naAbs.ConclusionIn the largest study focusing on a single ethnic and geographic group, we show that Japanese individuals with pre-existing naAbs have a much higher risk of life-threatening COVID-19 pneumonia.