Background: Loneliness is a critical social issue in older adults, with clinical implications. Conversational companion robots have been studied as one approach to ameliorating this issue. Large language models (LLMs) can enable flexible conversational ability in companion robots, but acceptability and suitability remain uncertain. We explored older people’s expectations and concerns regarding an LLM-supported companion robot for loneliness support. Methods: We conducted a UK–Japan qualitative study comprising hands-on focus groups for community-dwelling older adults in London (n=17) and a one-week in-home use with follow-up interviews in Osaka among outpatients with mild cognitive impairment (MCI; n=8). Transcripts were analysed using reflexive thematic analysis; for cross-site reporting, Japan themes/codes were mapped onto the thematic structure generated from the larger UK dataset. Descriptive questionnaire measures and at-home conversational log metrics were collected to contextualise qualitative findings. Results: Participants saw value of the companion robot as a support for older people with loneliness but emphasised that acceptability depends on interaction mechanics and user agency. Three cross-context themes were identified: (1) Practical use and functionality (response latency, turn-taking, desired features, and controllability in home use); (2) Emotional connection and engagement (social presence alongside perceived limits in conversational fit and depth); and (3) Ethical and societal reflections (privacy/data governance, access, and concerns about substituting for human contact). Conclusions: LLM-supported companion robots may provide acceptable low-intensity support for some older people, including those with MCI, provided that usability, user-adjustable control and ethical governance are prioritised. Longer deployments are needed to evaluate potential sustained benefit and burden.

Previous studies suggest that oxytocin has therapeutic potential for modulating core symptoms of autism spectrum disorder (ASD), although findings have been inconsistent. The unknown mechanisms underlying oxytocin's effects and the substantial individual variability in treatment response impede the development of effective oxytocin-based therapies. In this study, we conducted a genome-wide association study (GWAS) using data from a randomized controlled trial (RCT) that examined the effects of a single dose oxytocin on behavioral and neural correlates of ASD. We further tested the association between the SNP identified in the GWAS and clinical efficacy in an independent, larger dataset comprising participants from three additional RCTs. In these trials, males with high-functioning ASD received repeated doses of oxytocin, and treatment response was assessed using the social reciprocity domain of the Autism Diagnostic Observation Schedule (ADOS), the common primary outcome across all three studies. The GWAS identified a significant association between oxytocin-induced improvements in medial prefrontal cortex activity during a social judgment task and the single nucleotide polymorphism (SNP) rs1871303 in the ryanodine receptor 2 (RYR2) gene (β = 2.37, t = 7.82, df = 72, P = 3.47 × 10⁻⁹). The validation analysis supported the association between this RYR2 SNP and individual variability in ADOS reciprocity improvement (β = 0.194, t = 2.30, df = 135, P = 0.023), with no significant association observed for placebo response (P > 0.1). To our knowledge, this is the first GWAS to investigate the pharmacogenomics of oxytocin efficacy in ASD. These findings highlight RYR2 as a key gene influencing oxytocin response, possibly through its role in calcium channel signaling and regulation of endogenous oxytocin release.

Background The approval of lecanemab has created new operational demands for Alzheimer's disease care. Japan's nationwide rollout under universal health insurance offers an opportunity to identify real-world bottlenecks in treatment delivery. Objective To identify facility-level and infrastructure-level factors associated with wait time to initial lecanemab infusion and treated patient volume among dementia specialists in Japan. Methods We performed a secondary analysis of an anonymous online survey of 296 dementia specialists certified to prescribe lecanemab in Japan approximately one year after approval. We examined associations between physician/facility characteristics, diagnostic and infusion resources, perceived implementation barriers, and two delivery metrics: wait time from first consultation to first infusion and number of treated patients per respondent. Bayesian accelerated failure-time and zero-truncated Poisson mixed-effects models were used. Results Approximately 80% of respondents reported average wait times of 3 months or less, whereas the median treated caseload was modest at 5 patients per physician. Perceived mismatch between treatment capacity and demand was associated with longer wait time (time ratio 1.323, 95% credible interval 1.045–1.682). Cerebrospinal fluid (CSF)-dominant amyloid-testing strategies tended to be associated with smaller caseloads, while in-house CSF testing and APOE testing were associated with larger caseloads. High-volume centers reported constrained outpatient infusion space. Lack of reimbursement for infusion-related tasks and APOE testing were perceived as major system-level barriers. Conclusions Japan's rollout may be constrained by some bottlenecks in diagnostics, infusion infrastructure, and uncompensated tasks. Appropriate policy interventions might help secure equitable access to the treatment.

Impaired cerebrospinal fluid (CSF) dynamics may affect brain health in older adults and contribute to age-related changes in brain structure. Disproportionately enlarged subarachnoid-space hydrocephalus (DESH) is a neuroimaging finding associated with impaired CSF dynamics. However, the association between frailty—a condition characterised by increased vulnerability in late life—and DESH-related CSF space volumes remains poorly understood. Therefore, in this study, we aimed to investigate this association. This cross-sectional study was conducted using data from 1,395 community-dwelling Japanese adults aged ≥ 65 years without dementia. Frailty was assessed using the Japanese version of the Fried criteria, comprising slowness, weakness, low activity, shrinking, and exhaustion. Volumes of regions of interest (ROIs) were measured by magnetic resonance imaging, and DESH-related regions (ventricular system [VS], Sylvian fissures [SF], and the subarachnoid space at the high convexity and midline [SHM]) were quantified using voxel-based morphometry. Ordinal logistic regression analysis was conducted with frailty status (robust [reference], prefrail, or frail) as the dependent variable and each ROI volume as independent variables. The results showed positive associations of VS volume (odds ratio [OR] 1.21; 95

Although companion robots have demonstrated psychological benefits for older adults, most studies have focused on short-term use or institutional settings. This case series with integrated qualitative analysis describes five cases involving the long-term use of a conversational companion robot (RoBoHoN, Sharp) among community-dwelling women aged 85 to 90 with mild cognitive impairment or late-onset psychosis. After an initial exploratory phase (2-5 months) and a 2-month washout, the robot was installed in each home for 18 months. All participants operated the robot in daily life, with only intermittent light-touch support from caregivers or the team when needed. Usability assessments showed high satisfaction and ease of use. Although standardised psychological scales showed no consistent improvements, participants reported enjoying conversations with the robot. Four of the five expressed a desire to continue using the robot after the study. These findings support the feasibility and potential long-term acceptability of companion robots among cognitively challenged older adults living at home. The case series suggests such robots may foster sustained engagement even in vulnerable populations. Further studies with larger samples are needed to evaluate the psychological effects of long-term companion robot use in home settings.

BACKGROUND:Domain-level ADL and IADL independence across MMSE score ranges has been less well described in Alzheimer's disease (AD), dementia with Lewy bodies (DLB), and frontotemporal dementia (FTD). This study described the observed proportions of basic ADL and IADL independence across MMSE score ranges in these three neurodegenerative dementias. METHODS:In a cohort of 650 patients (524 AD, 90 DLB, 36 FTD), cognitive function was assessed with the Mini-Mental State Examination (MMSE), and daily function was evaluated using the Physical Self-Maintenance Scale and the Lawton IADL scale. Patients were grouped into MMSE score ranges. For each diagnosis and MMSE score range, we calculated the observed proportion of participants rated as independent in each ADL/IADL domain and Wilson score 95% confidence intervals. Because the FTD sample was small (n = 36), with only 1-11 participants in individual five-point MMSE score ranges, and several MMSE-specific subgroup counts were sparse, the analyses were descriptive. RESULTS:Observed independence proportions varied across ADL/IADL domains, MMSE score ranges, and diagnostic groups. In AD and DLB, shopping, food preparation, and medication management had low observed independence proportions even in higher MMSE ranges. In the MMSE 21-30 stratum, selected absolute numerical contrasts between DLB and AD ranged from 7.2 percentage points for feeding to 18.4 percentage points for bathing. Estimates for FTD, which were based on only 1-11 participants per five-point MMSE score range, and for DLB in the MMSE 0-10 stratum were based on small denominators and were therefore imprecise. CONCLUSIONS:This study provides descriptive estimates of domain-level ADL and IADL independence across MMSE score strata in AD, DLB, and FTD. The results may contribute to domain-specific assessment and support planning for people living at home with MCI or dementia. These findings should be regarded as hypothesis-generating for future studies.

Loneliness is a major psychological challenge in older adulthood, contributing to increased risks of depression, anxiety, and mortality. Conversational agents - technologies that interact with users via natural language - have emerged as potential tools to support psychological well-being in later life. This systematic review and meta-analysis evaluated the effects of autonomous conversational agents, including robotic and nonrobotic systems, on loneliness, as well as social isolation, depression, and anxiety in older people without cognitive impairment. Seventeen studies with pre-post intervention data were included. Nine used physically embodied robots and eight employed nonrobotic agents, such as personal voice assistants, chatbots, or screen-based embodied agents. Due to the limited number of high-quality comparison studies, all meta-analyses were based on within-group pre-post comparisons. Meta-analytic results showed mild to moderate improvements in loneliness (standardized mean changes using change score [SMCC] = 0.350, 95% confidence interval [CI]: 0.180-0.520) and depression (SMCC = 0.464, 95% CI: 0.327-0.602), with no study reporting symptom worsening. No study included validated measures of social isolation, and only one assessed anxiety. These findings indicate that conversational agents may offer scalable support for older adults' mental health, with potential especially for reducing loneliness and depression. Nonetheless, methodological limitations, including lack of blinded outcome assessment, inconsistent reporting, and heterogeneous intervention designs, underscore the need for more rigorous research. Advances in large language models may further enhance the responsiveness and relevance of these technologies for supporting psychological well-being in aging populations.

Loneliness in later life is a public‑health concern, and large language model (LLM)-enabled conversational robots have potential to supplement social connection at scale by facilitating everyday conversations. However, evidence on the development and acceptability of such systems for older people remains scarce. We conducted a two‑round mixed methods study with older community‑dwelling participants, to test whether pipeline refinements—streaming automatic speech recognition, text‑to‑speech, and simplified turn‑taking cues—improved conversational experience. A tabletop conversational robot (Sota, Vstone), powered by Generative Pre‑trained Transformer (GPT)‑4o was used. Eighteen individuals participated in round one; paired analyses were conducted on the 17 eligible participants remaining in round two. We collected interaction logs (response latency, LLM‑level latency, and deletion rate [proportion of words in the manual transcript omitted in the ASR output]), technical failure events, and participant questionnaires (Godspeed Questionnaire Series; System Usability Scale; a customised five-item scale assessing conversational experience). Qualitative data were analysed using a framework approach. Median response latency decreased from 9.8 to 4.7s, deletion rate from 0.37 to 0.07, accompanied by improved perceived usability and conversational naturalness, while questionnaire indices of companionship changed little. Qualitative accounts converged: interactions felt smoother and more in‑context, yet interruptions, perceived superficiality of conversation, and only a modest sense of companionship were still experienced. Findings indicate that improving basic conversational fluency enhances naturalness and usability but is insufficient for delivering truly relational experience outcomes. Progress toward better companionship requires an additional relational layer—shared memories, age‑attuned personas, and calibrated reciprocity.

Behavioral disinhibition is a core feature of behavioral variant frontotemporal dementia (bvFTD) and occurs across related FTD-spectrum presentations. Serotonergic dysfunction may contribute to behavioral dysregulation; therefore, we primarily examined dorsal raphe (DR)-centered midbrain ¹²³I-FP-CIT uptake as an indirect extrastriatal signal that may partly reflect serotonin transporter-related binding. Because striatal dopaminergic circuits support reward learning, behavioral inhibition, and context-dependent behavioral updating, striatal uptake was examined exploratorily. This retrospective exploratory study included 21 patients within the FTD spectrum who underwent Neuropsychiatric Inventory (NPI) assessment, magnetic resonance imaging, and ¹²³I-FP-CIT single-photon emission computed tomography within a 3-month window. The primary outcome was the NPI disinhibition score. DR-centered midbrain and striatal specific uptake ratios (SURs) were calculated using the cerebellum as the reference region. Age- and sex-adjusted quasi-Poisson models with a log link were fitted. DR-centered midbrain SUR was not significantly associated with disinhibition in the primary model (β = −1.027, p = 0.353). In the exploratory model, higher striatal SUR was nominally associated with lower disinhibition scores (β = −0.438, p = 0.022). The negative direction of the striatal association was generally preserved across sensitivity analyses, although nominal significance was not retained in all models. DR-centered midbrain SUR was not significantly associated with behavioral disinhibition in this small FTD-spectrum cohort. Lower striatal SUR showed a directionally consistent but sensitivity-dependent nominal association with greater disinhibition. This hypothesis-generating finding may reflect broader frontostriatal disease burden, striatal neurodegeneration, parkinsonian-spectrum overlap, or partial-volume effects and does not establish a disinhibition-specific dopaminergic mechanism.

AIM:To evaluate the effectiveness of sleep monitoring, report feedback, and telephone-based guidance regarding sleep hygiene and daytime activity for community-dwelling older adults. METHODS:We conducted a three-arm randomized controlled trial among community-dwelling adults in Japan. Participants were divided into three groups: (A) sleep report feedback and telephone-based health guidance for 6 months; (B) sleep report feedback and telephone-based health guidance for the first 3 months followed by sleep report feedback alone for the subsequent 3 months; and (C) sleep report feedback alone for 6 months. All groups used a sleep monitoring device. The Athens Insomnia Scale (AIS) score was the primary outcome. We analyzed time-series data by comparing different groups before and after the intervention to determine factors influencing the AIS score. All significance levels were set at p < 0.05. RESULTS:In total, 229 participants (80, 74, and 75 participants in groups A, B, and C, respectively) were randomized (men: 37.1%; mean age: 78.5 years; average AIS score: 6.5). Linear mixed model analysis revealed a significant group-by-time interaction for AIS scores (p = 0.002). Both intervention groups showed significant within-group improvements in AIS scores at 3 months compared with baseline, whereas the control group showed no significant change over time. In between-group comparisons, Group B showed significantly lower AIS scores than the control group at 3 months. CONCLUSIONS:Combining sleep report feedback with telephone-based health guidance may support improvement in subjective sleep status among community-dwelling older adults. TRIAL REGISTRATION:Committee and registered in the UMIN Clinical Trials Registry (study number: 21249; date of first registration: December 15, 2021; receipt number: R000052743; https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000052743).

Dementia with Lewy bodies has a complex clinical presentation, with symptoms spanning cognitive, neuropsychiatric, motor, autonomic, and sleep domains. The disorder causes high morbidity, is associated with high caregiver burden, and can result in considerable health-care costs. Although symptomatic treatments remain scarce, emerging evidence supports a multipronged approach that integrates pharmacological and non-pharmacological interventions that target different signs and symptoms. Novel frameworks, such as the DIAMOND Lewy toolkit, provide structured management guidance. Beyond symptom control, research is at a turning point, with increasing focus on disease-modifying therapies. Ongoing clinical trials are exploring many therapeutic targets, including alpha-synuclein aggregation and neuroinflammation. Other potential targets in the treatment of dementia with Lewy bodies include amyloid beta, given that the presence of Alzheimer's disease copathology is common in patients with this disease.

The global increase in number of people living with dementia and its mental health implications is closely linked to the development of Old Age Psychiatry (OAP) in the past 50 years. OAP focuses on addressing the complex psychiatric and physical needs of older adults, particularly those with dementia. Reflecting on the significance of early neuropsychiatric symptoms (NPS) in dementia, recent breakthroughs in early diagnostics and the amyloid targeting therapy (ATT) for Alzheimer's disease, it is time to examine the ongoing challenges and the role of OAP clinicians in managing dementia. The future of collaboration with medical, technological, and social experts presents opportunities for OAP to optimize dementia care beyond medication or social assistance, addressing the needs of people living with and their families along the whole disease spectrum.

BACKGROUND:Since research on the pathophysiology of psychiatric disorders diagnosed by symptoms has not succeeded, a data-driven analysis incorporating biological and cross-disease perspectives has been proposed. We have reported a new subgroup of psychiatric disorders by a data-driven analysis of subcortical volumes of brain MRI in 5602 subjects, including patients with psychiatric disorders and controls. This subgroup of patients is characterized by enlarged ventricle and cognitive impairment (EVCI) with a high proportion of schizophrenia, electroencephalography abnormalities, and rare pathological copy number variations. CASE PRESENTATION:Of the nine patients with EVCI, eight patients had schizophrenia, and one patient had autism spectrum disorder. Early onset of age was observed in eight patients with schizophrenia. Treatment responses were poor in seven patients with schizophrenia, and two of three treatment-resistant schizophrenia patients responded to clozapine. Four patients showed ischemic changes in cerebral white matter. In electroencephalography, abnormal findings were observed in five patients, borderline findings in two patients, and normal findings in two patients. Rare pathogenic copy number variations were found in three patients (22q11.21 deletion, 7q11.23 duplication, and 7q36.2 deletion). CONCLUSIONS:The results of this case series showed additional clinical features of treatment response and ischemic changes in cerebral white matter, which could be a clue to the treatment and diagnosis of EVCI. This case series might help elucidate the pathophysiology of EVCI.

BACKGROUND:Sleep quality is crucial for maintaining and enhancing health and quality of life in older adults. However, the specific components of sleep-related lifestyle advice associated with improved sleep quality remain unclear. This exploratory study aimed to describe the themes of personalised health guidance provided to community-dwelling older adults by targeting those whose scores on the Athens Insomnia Scale (AIS), a validated self-reported measure of insomnia severity, improved after an intervention that combined sleep monitoring and personalised health guidance. METHODS:In a 3-month intervention, 12 trained healthcare professionals (including nurses and public health nurses) delivered individualized health guidance using sleep data obtained from a non-wearable actigraphy device, the Active Sleep Analyser. Among them, 11 provided guidance to the participants whose data were included in the present analysis. Of the 168 older adults who received the intervention, the data from 162 participants with complete AIS scores were analyzed. From this group, 57 individuals who displayed improvements in their AIS severity classification over a 3-month period were selected for qualitative analysis. The guidance sessions were recorded, transcribed verbatim, and analyzed using an inductive content analysis approach. RESULTS:The analysis revealed seven major categories comprising 18 sub-categories. The categories were: (1) Praise for improvements in sleep quality and behavioural change efforts; (2) evaluation and continuous support for behaviour change; (3) establishing appropriate napping habits; (4) developing a healthy daily routine and rhythm; (5) establishing appropriate sleep habits; (6) addressing factors affecting sleep quality; and (7) appropriate medical advice and recommendations to consult physicians. CONCLUSIONS:This exploratory study described the themes observed in the personalized health guidance provided to older adults who showed improvements in AIS scores. These findings provide descriptive insights and may inform the development of future interventions or hypothesis-driven studies to support sleep health among community-dwelling older adults.