Hiroyuki Toda

Aim: The objective of this study was to evaluate the potential of hydrogen in preventing and treating psychiatric symptoms, particularly depressed mood and loss of interest, and to explore its underlying mechanisms. A mouse model exhibiting inflammation‐derived depressive symptoms was used for the investigation.Methods: Institute of Cancer Research mice were subjected to a 7‐day intervention of either 30% hydrogen or 40 g per day of air via jelly intake. On the final day, lipopolysaccharide (LPS) was intraperitoneally administered at 5 mg/kg to induce inflammation‐related depressive symptoms. Behavioral and biochemical assessments were conducted 24 h post‐LPS administration.Results: Following LPS administration, a decrease in spontaneous behavior was observed; however, this effect was mitigated in the group treated with hydrogen. The social interaction test revealed a significant reduction in interactions with unfamiliar mice in the LPS‐treated group, whereas the hydrogen‐treated group exhibited no such decrease. No significant changes were noted in the forced‐swim test for either group. Additionally, the administration of LPS in the hydrogen group did not result in a decrease in zonula occludens‐1, a biochemical marker associated with barrier function at the cerebrovascular barrier and expressed in tight junctions.Conclusion: Hydrogen administration demonstrated a preventive effect against the LPS‐induced loss of interest, suggesting a potential role in symptom prevention. However, it did not exhibit a suppressive effect on depressive symptoms in this particular model. These findings highlight the nuanced impact of hydrogen in the context of inflammation‐induced psychiatric symptoms, indicating potential avenues for further exploration and research.

Extracellular vesicles (EVs), nano particles secreted by all types of cells, serve as a communication network, carrying information through the bloodstream to distant cells ^1,2 . Notably, brain cells secrete EVs that play a crucial role in regulating neurological functions ^3-5 . Meanwhile the brain detects acute stress and activates mechanisms to enhance stress resistance and maintain homeostasis ^6,7 . However, the specific contribution of brain-derived extracellular vesicles (BDEVs) in modulating the stress response remains elusive. Here we found that administration of the acute stress-induced BDEVs to mice reduced anxiety-related behaviours, and this reduction was also induced by the administration of only three microRNAs (miRNAs) (miR-199a-3p, miR-99b-3p and miR-140-5p) included in the acute stress-induced BDEVs. Furthermore, we showed that miR-199a-3p contributes to the mechanism of the anxiolytic effect through the suppression of Mecp2 in neurons. These findings elucidate the role of BDEVs in modulating mental activity under acute stress and provide insights into the underlying molecular mechanisms. Our results open up new avenues for therapeutic strategies in the treatment of anxiety disorders using EVs or miRNAs.

Burnout and secondary traumatic stress (STS), also referred to as compassion fatigue, are undeniable negative consequences experienced by healthcare professionals when working with patients. As frontline healthcare professionals are essential to communities, it is crucial to understand their mental health and how they cope with negative psychological responses. This study investigated the relationships between burnout, STS, compassion satisfaction, dispositional empathy, and stress management among Japanese healthcare professionals and students taking care of patients in clinical practice. The participants were 506 Japanese healthcare professionals and students (doctors, nurses, medical students, and nursing students) affiliated with Japanese Ministry of Defense Hospitals. The data were collected from March 2020 to May 2021. We assessed burnout, STS, and compassion satisfaction using the Professional Quality of Life Scale, dispositional empathy using the Interpersonal Reactivity Index, and coping with stress using the Coping Orientation to Problems Experienced Inventory (Brief-COPE). Exploratory factor analysis of the Brief-COPE yielded three factors: active coping; support-seeking; and indirect coping. Personal distress, a self-oriented emotional empathy index, was related to higher burnout and STS scores and lower compassion satisfaction. Empathic concern, an other-oriented emotional empathy index, was associated with lower burnout and higher compassion satisfaction. Active coping strategies were associated with lower burnout and higher compassion satisfaction, whereas indirect coping strategies were associated with higher burnout and STS scores. In a comparison of empathy in professional categories, nurses presented higher personal distress than nursing students, and medical doctors showed lower fantasy tendencies than medical students. These results imply the complex relationships between empathy, coping strategies, and psychological responses among healthcare professionals. Further longitudinal study is needed to explore these complex relationships and to develop more precise and effective psycho-educational interventions to prevent burnout and STS.

Aim: Bipolar disorder is a leading disorder contributing to global disease burden, and bipolar depression often becomes severe and refractory. Therefore, clarifying the pathophysiology of bipolar disorder is an urgent issue. Previous reports suggested that factors, such as affective temperaments and childhood maltreatment, aggravate bipolar depression severity. However, to our knowledge, no reports to date have clarified the interrelationship between the above factors and bipolar depression severity. We here hypothesized that childhood maltreatment worsens bipolar depression severity via increasing affective temperaments. To test this hypothesis, a covariance structural analysis was conducted.Methods: The following information was evaluated for a total of 75 people with bipolar disorder using self‐administered questionnaires: demographic characteristics, depressive symptoms (Patient Health Questionnaire‐9), history of childhood maltreatment (Child Abuse and Trauma Scale), and affective temperaments (Temperament Evaluation of Memphis, Pisa, Paris, and San Diego Autoquestionnaire). The results were analyzed using covariance structure analysis.Results: A significant indirect effect of childhood maltreatment on bipolar depression severity via increasing affective temperaments was identified, whereas the direct effect of childhood maltreatment was not significant.Conclusion: Our results reveal that affective temperaments can mediate the adverse effects of childhood maltreatment on the severity of bipolar depression.

Voice-based depression detection methods have been studied worldwide as an objective and easy method to detect depression. Conventional studies estimate the presence or severity of depression. However, an estimation of symptoms is a necessary technique not only to treat depression, but also to relieve patients’ distress. Hence, we studied a method for clustering symptoms from HAM-D scores of depressed patients and by estimating patients in different symptom groups based on acoustic features of their speech. We could separate different symptom groups with an accuracy of 79%. The results suggest that voice from speech can estimate the symptoms associated with depression.

In general, it is common knowledge that people’s feelings are reflected in their voice and facial expressions. This research work focuses on developing techniques for diagnosing depression based on acoustic properties of the voice. In this study, we developed a composite index of vocal acoustic properties that can be used for depression detection. Voice recordings were collected from patients undergoing outpatient treatment for major depressive disorder at a hospital or clinic following a physician’s diagnosis. Numerous features were extracted from the collected audio data using openSMILE software. Furthermore, qualitatively similar features were combined using principal component analysis. The resulting components were incorporated as parameters in a logistic regression based classifier, which achieved a diagnostic accuracy of ~90% on the training set and ~80% on the test set. Lastly, the proposed metric could serve as a new measure for evaluation of major depressive disorder.

Fall from a height is a common cause of trauma requiring emergency care; in many cases, the trauma team needs to urgently develop the initial treatment strategy. The mechanism of injury (intentional or accidental) is an important factor in predicting trauma patterns and severity. We aimed to describe how the severity of injuries in each body region contributes to overall trauma severity and skeletal trauma patterns in intentional and accidental falls. Data accumulated between January 1, 2004 and May 31, 2019 were obtained from a nationwide trauma database. Patients aged ≥18 years and injured by falls from a height were included. The median Abbreviated Injury Scale (AIS) score for the Injury Severity Score (ISS) for each body region (region 1: head, face, and neck; region 2: thorax; region 3: abdomen; region 4: lower extremity and pelvis; and region 5: upper extremity) was investigated. Skeletal injury patterns were classified into four groups: group I (intentional/severe), group II (accidental/severe), group III (intentional/not severe), and group IV (accidental/not severe). Severe trauma was defined as a trauma with an ISS of 16 or more. The groups were compared using the chi-square test and Mann-Whitney U test. Among the 342,263 patients enrolled in the database, 28,409 met the inclusion criteria: 6,812 in group I, 11,754 in group II, 2,384 in group III, and 7,459 in group IV. The intentional fall group showed an increase in the AIS score for region 4 as the ISS increased, whereas the accidental fall group showed an increase in the AIS score for region 1. Both groups showed an increase in the AIS score for region 2 as the ISS increased. The intentional fall group had a higher proportion of fractures in the lower extremities and pelvis than the accidental fall group. There were differences in trauma patterns and trauma severity levels between patients who experienced intentional and accidental falls from a height. Our findings provide a comprehensive understanding of this topic. Further studies are required to assess the usefulness of our findings for the development of initial treatment strategies at the ED.