Epidemiology of coronavirus disease 2019 (COVID-19) in Japan during the first and second waves

Following the emergence and worldwide spread of coronavirus disease 2019 (COVID-19), each country has attempted to control the disease in different ways. The first patient with COVID-19 in Japan was diagnosed on 15 January 2020, and until 31 October 2020, the epidemic was characterized by two large waves. To prevent the first wave, the Japanese government imposed several control measures such as advising the public to avoid the 3Cs (closed spaces with poor ventilation, crowded places with many people nearby, and close-contact settings such as close-range conversations) and implementation of "cluster buster" strategies. After a major epidemic occurred in April 2020 (the first wave), Japan asked its citizens to limit their numbers of physical contacts and announced a non-legally binding state of emergency. Following a drop in the number of diagnosed cases, the state of emergency was gradually relaxed and then lifted in all prefectures of Japan by 25 May 2020. However, the development of another major epidemic (the second wave) could not be prevented because of continued chains of transmission, especially in urban locations. The present study aimed to descriptively examine propagation of the COVID-19 epidemic in Japan with respect to time, age, space, and interventions implemented during the first and second waves. Using publicly available data, we calculated the effective reproduction number and its associations with the timing of measures imposed to suppress transmission. Finally, we crudely calculated the proportions of severe and fatal COVID-19 cases during the first and second waves. Our analysis identified key characteristics of COVID-19, including density dependence and also the age dependence in the risk of severe outcomes. We also identified that the effective reproduction number during the state of emergency was maintained below the value of 1 during the first wave

Evaluation of an association between plasma total homocysteine and schizophrenia by a Mendelian randomization analysis

Background: The results of meta-analyses conducted by previous association studies between total homocysteine and schizophrenia suggest that an elevated total homocysteine level is a risk factor for schizophrenia. However, observational studies have potential limitations, such as confounding and reverse causation. In the present study, we evaluated a causal relationship between plasma total homocysteine and schizophrenia by conducting a Mendelian randomization analysis. Methods: We used the MTHFR C677T polymorphism as an instrumental variable, which affects the plasma total homocysteine levels. To calculate the risk estimate for the association of this single nucleotide polymorphism (SNP) with schizophrenia, we conducted a meta-analysis of case–control studies that comprise a total of 11,042 patients with schizophrenia and 14,557 control subjects. We obtained an estimate for the association of this SNP with the plasma total homocysteine levels from a meta-analysis of genome-wide association studies comprising 44,147 individuals. Results: By combining these two estimates, we demonstrated a significant effect of the plasma total homocysteine on schizophrenia risk, representing an OR of 2.15 (95 % CI = 1.39–3.32; p = 5.3 x 10−4) for schizophrenia per 1-SD increase in the natural log-transformed plasma total homocysteine levels. Conclusions: We provided evidence of a causal relationship between the plasma total homocysteine and schizophrenia, and this result will add insight into the pathology and treatment of schizophrenia

Association between BDNF and clinical response in OCD

Aim: Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family, and it promotes the development and function of dopaminergic and serotonergic neurons. The Met allele of the BDNF Val66Met polymorphism is associated with a decrease in activity-dependent secretion of BDNF compared with the Val allele, and a number of studies have provided evidence for the association between this polymorphism and obsessive-compulsive disorder (OCD). The purpose of this study was to investigate whether this functional variant of the BDNF gene is associated with OCD and treatment response in patients with OCD in the Japanese population. Methods: We first performed a case–control association study between the BDNF Val66Met polymorphism and OCD (175 cases and 2,027 controls). Then, we examined an association between this polymorphism and treatment response in 96 patients with OCD. Results: We found no significant association between the Met allele and OCD risk or between the Met allele and treatment responses to selective serotonin reuptake inhibitors or serotonin reuptake inhibitor with an atypical antipsychotic (P>0.05). Conclusion: Our results suggest that the BDNF Val66Met polymorphism may not be associated as a risk factor for developing OCD or with therapeutic response in patients with OCD in the Japanese population

Left Side Electrode of DBS Caused an Acute Mood Swing

No previous reports have described a case in which deep brain stimulation elicited an acute mood swing from a depressive to manic state simply by switching one side of the bilateral deep brain stimulation electrode on and off. The patient was a 68-year-old woman with a 10-year history of Parkinson’s disease. She underwent bilateral subthalamic deep brain stimulation surgery. After undergoing surgery, the patient exhibited hyperthymia. She was scheduled for admission. On the first day of admission, it was clear that resting tremors in the right limbs had relapsed and her hyperthymia had reverted to depression. It was discovered that the left-side electrode of the deep brain stimulation device was found to be accidentally turned off. As soon as the electrode was turned on, motor impairment improved and her mood switched from depression to mania. The authors speculate that the lateral balance of stimulation plays an important role in mood regulation. The current report provides an intriguing insight into possible mechanisms of mood swing in mood disorders

A gene expression test for depression

Purpose: Recently, we could distinguished patients with major depressive disorder (MDD) from nonpsychiatric controls with high accuracy using a panel of five gene expression markers (ARHGAP24, HDAC5, PDGFC, PRNP, and SLC6A4) in leukocyte. In the present study, we examined whether this biological test is able to discriminate patients with MDD from those without MDD, including those with schizophrenia and bipolar disorder. Patients and methods: We measured messenger ribonucleic acid expression levels of the aforementioned five genes in peripheral leukocytes in 17 patients with schizophrenia and 36 patients with bipolar disorder using quantitative real-time polymerase chain reaction (PCR), and we combined these expression data with our previous expression data of 25 patients with MDD and 25 controls. Subsequently, a linear discriminant function was developed for use in discriminating between patients with MDD and without MDD. Results: This expression panel was able to segregate patients with MDD from those without MDD with a sensitivity and specificity of 64% and 67.9%, respectively. Conclusion: Further research to identify MDD-specific markers is needed to improve the performance of this biological test

Aripiprazole augmentation to antidepressant therapy in Japanese patients with major depressive disorder: A randomized, double-blind, placebo-controlled study (ADMIRE study)

AbstractObjectiveThis randomized, placebo-controlled study evaluated the efficacy and safety of a fixed dose (3mg/day) and flexible dose (3–15mg/day) schedule of aripiprazole as augmentation therapy in Japanese patients with inadequate response to antidepressant therapy (ADT).MethodDuring an 8-week prospective treatment phase, patients experiencing a major depressive episode received clinicians' choice of ADT. Subjects with inadequate response to ADT were randomized to receive adjunctive treatment with placebo (n=195), fixed dose aripiprazole (n=197) or flexible dose aripiprazole (n=194) for 6 weeks. The primary efficacy endpoint was mean change in the Montgomery–Åsberg Depression Rating Scale (MADRS) total score from the end of prospective treatment (baseline) to the end of randomized treatment.ResultsMore than 90% of patients in all treatment groups completed the 6-week double-blind treatment phase. Mean MADRS total score was improved to a significantly greater extent with fixed dose aripiprazole and flexible dose aripiprazole (−10.5 and −9.6, respectively) than with placebo (−7.4). Aripiprazole was well tolerated. The incidence of akathisia observed in the flexible dose group may relate to a higher prevalence of the CYP2D6*10 allele in Asian populations.LimitationsSix weeks of adjunctive treatment is insufficient to draw conclusions about the long-term benefits of aripiprazole. Exclusion of patients with established medical comorbidities does not reflect real-world practice.ConclusionsAripiprazole augmentation at a fixed or flexible dose was superior to ADT alone and was reasonably well tolerated in Japanese patients with inadequate response to ADT.Clinical trials registrationClinicalTrials.gov identifier NCT00876343

Decelerated epigenetic aging associated with mood stabilizers in the blood of patients with bipolar disorder

There is high mortality among patients with bipolar disorder (BD). Studies have reported accelerated biological aging in patients with BD. Recently, Horvath and Hannum et al. independently developed DNA methylation (DNAm) profiles as “epigenetic clocks,” which are the most accurate biological age estimate. This led to the development of two accomplished measures of epigenetic age acceleration (EAA) using blood samples, namely, intrinsic and extrinsic EAA (IEAA and EEAA, respectively). IEAA, which is based on Horvath’s clock, is independent of blood cell counts and indicates cell-intrinsic aging. On the other hand, EEAA, which is based on Hannum’s clock, is associated with age-dependent changes in blood cell counts and indicates immune system aging. Further, Lu et al. developed the “GrimAge” clock, which can strongly predict the mortality risk, and DNAm-based telomere length (DNAmTL). We used a DNAm dataset from whole blood samples obtained from 30 patients with BD and 30 healthy controls. We investigated Horvath EAA, IEAA, Hannum EAA, EEAA, Grim EAA, DNAmTL, and DNAm-based blood cell composition. Compared with controls, there was a decrease in Horvath EAA and IEAA in patients with BD. Further, there was a significant decrease in Horvath EAA and IEAA in patients with BD taking medication combinations of mood stabilizers (including lithium carbonate, sodium valproate, and carbamazepine) than in those taking no medication/monotherapy. This study provides novel evidence indicating decelerated epigenetic aging associated with mood stabilizers in patients with BD

Folate and gender in schizophrenia

Aim: Gender differences in serum folate concentrations are well known, but no studies have investigated the association between serum folate levels and schizophrenia based on gender. In this study in a Japanese population, we examined the difference in serum folate levels between patients with schizophrenia and non‐psychiatric controls stratified by gender. The relationships between serum folate levels, plasma total homocysteine (tHcy) and serum vitamin B6 (pyridoxal) levels were also examined using data from our previous studies. Methods: The serum folate concentrations of 482 patients diagnosed with schizophrenia and 1,350 non‐psychiatric control subjects were measured. We conducted an analysis of covariance to examine the differences in serum folate levels between the two groups based on gender. Spearman’s rank correlation was used to evaluate the relationships between folate, tHcy and vitamin B6 levels. Results: In the control group, serum folate concentrations were higher in women than in men. Lower levels of serum folate were observed in both male and female patients with schizophrenia. An inverse correlation between serum folate and plasma tHcy and a weak positive correlation between serum folate and vitamin B6 were observed in the combined cohort. Conclusion: Our findings suggest that (1) a low serum folate level may be associated with schizophrenia regardless of gender, and (2) folate administration may be beneficial for the treatment of schizophrenia. In schizophrenic patients with low serum folate levels, folate administration might result in improvements in high tHcy and an increase in low vitamin B6 levels

Blood glutamate levels were significantly higher in MDD patients

Purpose: There is growing evidence that glutamatergic signaling may be involved in major depressive disorder (MDD). In regard to peripheral blood glutamate changes in MDD, inconsistent findings have been reported. The purpose of the present study was to evaluate whether blood glutamate levels differed between MDD patients and control participants. Materials and methods: We conducted a systematic review and meta-analysis of 12 association studies between blood glutamate levels and MDD in a total of 529 MDD patients and 590 controls. Subsequently, we conducted subgroup analyses and a meta-regression analysis to examine the sources of potential heterogeneity. Results: A random effects model showed that blood glutamate levels were significantly higher in MDD patients than in controls (standardized mean difference=0.54, 95% CI=0.27–0.82, p=8.5×10-5) with high heterogeneity (I2=75.0%, p<0.05). Subgroup analyses showed elevated glutamate levels in MDD patients compared with controls in plasma, but not serum studies, and in studies using high-performance liquid chromatography but not with mass spectrometry for glutamate assay. A meta-regression analysis showed no effects of age, gender, medication use, sample size, and published year on blood glutamate levels. Conclusion: Our findings suggest that altered glutamate levels may be implicated in MDD, which provides further evidence of glutamatergic dysfunction in MDD