Akihiro Takamiya

• MD PhD
• Medical Doctor at Keio University

Background Late-life depression (LLD) is characterized by medial temporal lobe (MTL) abnormalities. Although gray matter (GM) and white matter (WM) differences in LLD have been reported, few studies have investigated them concurrently. Moreover, the impact of aetiological factors, such as neurodegenerative and cerebrovascular burden, on tissue diff...

Electroconvulsive therapy (ECT) is one of the most effective treatments for depression. ECT induces volume changes in the amygdala, a key center of anxiety. However, the clinical relevance of ECT-induced changes in amygdala volume remains uncertain. We hypothesized that nuclei-specific amygdala volumes and anxiety symptoms in depression could expla...

Exploring the neurobiological effects of various treatments for depression is pivotal in elucidating shared and unique mechanisms of action that may explain commonalities and differences in treatment outcomes. The amygdala, consisting of subdivisions with distinct roles in emotional processing, is thought to be implicated in the pathophysiology of...

Objective: To identify the COVID-19 impact on well-being/mental health, coping strategies and risk factors in adolescent worldwide. Method: Anonymous online multi-national/language survey in the general population (representative/weighted non-representative samples, 14-17years), measuring change in well-being (WHO-5/range=0-100) and psychopathology...

There is no multi-country/multi-language study testing a-priori multivariable associations between non-modifiable/modifiable factors and validated wellbeing/multidimensional mental health outcomes before/during the COVID-19 pandemic. Moreover, studies during COVID-19 pandemic generally do not report on representative/weighted non-probability sample...

Neuroimaging databases for neuro‐psychiatric disorders enable researchers to implement data‐driven research approaches by providing access to rich data that can be used to study disease, build and validate machine learning models, and even redefine disease spectra. The importance of sharing large, multi‐center, multi‐disorder databases has graduall...

Background The impact of the gut microbiota on neuropsychiatric disorders has gained much attention in recent years; however, comprehensive data on the relationship between the gut microbiome and its metabolites and resistance to treatment for depression and anxiety is lacking. Here, we investigated intestinal metabolites in patients with depressio...

Introduction:Maintaining remission after electroconvulsive therapy (ECT) is of clinical relevance in patients with depression, and maintenance ECT is introduced in patients who fail to maintain remission after ECT. However, the clinical characteristics and the biological background of patients who receive maintenance ECT are barely understood. Meth...

Objective:Depression is common in neurodegenerative diseases, and a psychiatric diagnosis of late-life depression (LLD) may be changed to neurodegenerative disease during the follow-up period. The aim of this study was to identify clinical characteristics of LLD that might be prodromal state of neurodegenerative diseases. Methods:We conducted a ret...

Depression is a highly prevalent and disabling psychiatric disorder. The hippocampus, which plays a central role in mood regulation and memory, has received considerable attention in depression research. Electroconvulsive therapy (ECT) is the most effective treatment for severe pharmacotherapy‐resistant depression. Although the working mechanism of...

Electroconvulsive therapy (ECT) is one of the most effective psychiatric treatments but the underlying mechanisms are still unclear. In vivo human magnetic resonance imaging (MRI) studies have consistently reported ECT-induced transient hippocampal volume increases, and an animal model of ECT (electroconvulsive stimulation: ECS) was shown to increa...

Two recent clinical trials, KetECT and ELEKT-D, compared the effectiveness of ketamine and electroconvulsive therapy (ECT) for major depressive disorder. Notably, these trials reported marked differences in ECT’s clinical outcomes of, with remission rates of 63% for KetECT and a strikingly lower rate of 22% for ELEKT-D, while the remission rates fo...

Aim Live two‐way video, easily accessible from home via smartphones and other devices, is becoming a new way of providing psychiatric treatment. However, lack of evidence for real‐world clinical setting effectiveness hampers its approval by medical insurance in some countries. Here, we conducted the first large‐scale pragmatic, randomized controlle...

Neurostimulation is a mainstream treatment option for major depression. Neuromodulation techniques apply repetitive magnetic or electrical stimulation to some neural target but significantly differ in their invasiveness, spatial selectivity, mechanism of action, and efficacy. Despite these differences, recent analyses of transcranial magnetic stimu...

Background: The COVID-19 pandemic has transformed healthcare significantly and telepsychiatry is now the primary means of treatment in some countries. Aims: To compare the efficacy of telepsychiatry and face-to-face treatment. Method: A comprehensive meta-analysis comparing telepsychiatry with face-to-face treatment for psychiatric disorders....

Background: Very-late-onset schizophrenia-like psychosis (VLOSLP) is associated with significant burden. Its clinical importance is increasing as the global population of older adults rises, yet owing to limited research in this population, the neurobiological underpinnings of VLOSP remain insufficiently clarified. Here we address this knowledge g...

Electroconvulsive therapy (ECT) is the most effective psychiatric treatment but the underlying mechanisms are still unclear. In vivo human magnetic resonance imaging (MRI) studies have consistently reported ECT-induced transient hippocampal volume increases, and an animal model of ECT (electroconvulsive stimulation: ECS) was shown to increase neuro...

Introduction Parents have significant genetic and environmental influences, which are known as intergenerational effects, on the cognition, behavior, and brain of their offspring. These intergenerational effects are observed in patients with mood disorders, with a particularly strong association of depression between mothers and daughters. Objecti...

Neurostimulation is a mainstream treatment option for major depression. Neuromodulation techniques apply repetitive magnetic or electrical stimulation to some neural target but significantly differ in their invasiveness, spatial selectivity, mechanism of action, and efficacy. Despite these differences, recent analyses of transcranial magnetic stimu...

Background: Maintaining remission after electroconvulsive therapy (ECT) is clinically relevant in patients with depression, and maintenance ECT has been introduced in patients who fail to maintain remission after ECT. However, the clinical characteristics and biological background of patients who receive maintenance ECT are poorly understood. Thus...

Objective: Electroconvulsive therapy (ECT) is the most effective treatment for patients with severe major depressive disorder (MDD). Given the known sex differences in MDD, improved knowledge may provide more sex-specific recommendations in clinical guidelines and improve outcome. In the present study we examine sex differences in ECT outcome and...

Background: The Collaborative Outcome study on Health and Functioning during Infection Times (COH-FIT; www.coh-fit.com) is an anonymous and global online survey measuring health and functioning during COVID-19 pandemic. The aim of this study was to test concurrently the validity of COH-FIT items and the internal validity of the co-primary outcome,...

Introduction Few biomarkers can be used clinically to diagnose and assess the severity of depression. However, a decrease in activity and sleep efficiency can be observed in depressed patients, and recent technological developments have made it possible to measure these changes. In addition, physiological changes, such as heart rate variability, ca...

Introduction Psychiatric disorders are diagnosed through observations of psychiatrists according to diagnostic criteria such as the DSM-5. Such observations, however, are mainly based on each psychiatrist's level of experience and often lack objectivity, potentially leading to disagreements among psychiatrists. In contrast, specific linguistic feat...

Aim: We applied natural language processing and machine learning to explore the disease-related language patterns which deserve objective measures for assessing language ability in Japanese patients with Alzheimer disease, while most previous studies have used large publicly available datasets in Euro-American languages. Methods: We obtained 276...

Background: Maintaining remission after electroconvulsive therapy (ECT) is clinically relevant in patients with depression, and maintenance ECT has been introduced in patients who fail to maintain remission after ECT. However, the clinical characteristics and biological background of patients who receive maintenance ECT are poorly understood. Thus,...

Background Electroconvulsive therapy (ECT) is provided for patients with severe and often life-threatening illness, who lack decision making capacity to consent to treatment (DMC-T) in clinical settings. Objective The aim of this study is to summarize previous studies investigating clinical outcomes of ECT in patients lacking DMC-T. Methods A sys...

Objective: Previous prediction models for electroconvulsive therapy (ECT) responses have predominantly been based on neuroimaging data, which has precluded widespread application for severe cases in real-world clinical settings. The aims of this study were (1) to build a clinically useful prediction model for ECT remission based solely on clinical...

Aim: Parents have significant genetic and environmental influences, which are known as intergenerational effects, on the cognition, behavior, and brain of their offspring. These intergenerational effects are observed in patients with mood disorders, with a particularly strong association of depression between mothers and daughters. The main purpos...

Objective Although anesthetics play an important role in electroconvulsive therapy (ECT), the clinical efficacy and seizure adequacy of sevoflurane in the course of ECT remain unclear. The purpose of this study was to examine the clinical efficacy and seizure adequacy of sevoflurane, compared with those of thiopental, in the course of ECT in patien...

Introduction Few biomarkers can be clinically used to diagnose and assess the severity of depression. However, a decrease in activity and sleep efficiency can be observed in depressed patients, and recent technological developments have made it possible to measure these changes. In addition, physiological changes, such as heart rate variability, ca...

Background: . High-quality comprehensive data on short-/long-term physical/mental health effects of the COVID-19 pandemic are needed. Methods: . The Collaborative Outcomes study on Health and Functioning during Infection Times (COH-FIT) is an international, multi-language (n=30) project involving >230 investigators from 49 countries/territories/re...

a b s t r a c t Background: Electroconvulsive therapy (ECT) is provided for patients with severe and often lifethreatening illness, who lack decision making capacity to consent to treatment (DMC-T) in clinical settings. Objective: The aim of this study is to summarize previous studies investigating clinical outcomes of ECT in patients lacking DMC-T...

Multichannel near-infrared spectroscopy (NIRS), including 52-channel NIRS (52ch-NIRS), has been used increasingly to capture hemodynamic changes in the brain because of its safety, low cost, portability, and high temporal resolution. However, optode caps might cause pain and motion artifacts if worn for extended periods of time because of the weigh...

Introduction: Psychiatric disorders are diagnosed according to diagnostic criteria such as the DSM-5 and ICD-11. Basically, psychiatrists extract symptoms and make a diagnosis by conversing with patients. However, such processes often lack objectivity. In contrast, specific linguistic features can be observed in some psychiatric disorders, such as...

Psychotic major depression (PMD) is hypothesized to be a distinct clinical entity from nonpsychotic major depression (NPMD). However, neurobiological evidence supporting this notion is scarce. The aim of this study is to identify gray matter volume (GMV) differences between PMD and NPMD and their longitudinal change following electroconvulsive ther...

250/250 Background : The COVID-19 pandemic has altered daily routines and family functioning, led to closing schools, and dramatically limited social interactions worldwide. Measuring its impact on mental health of vulnerable children and adolescents is crucial. Methods : The Collaborative Outcome study on Health and Functioning during Infection...

Introduction The COVID-19 pandemic has had a profound impact on the mental health of people around the world. Anxiety related to infection, stress and stigma caused by the forced changes in daily life have reportedly increased the incidence and symptoms of depression, anxiety disorder and obsessive-compulsive disorder. Under such circumstances, tel...

Electroconvulsive therapy (ECT) is the most effective antidepressant treatment, although its mechanisms of action remain unclear. Since 2010, several structural magnetic resonance imaging studies based on a neuroplastic hypothesis have consistently reported increases in the hippocampal volume following ECT. Moreover, volume increases in the human d...

Late-life depression (LLD) is associated with a risk of developing Alzheimer’s disease (AD). However, the role of AD-pathophysiology in LLD, and its association with clinical symptoms and cognitive function are elusive. In this study, one hundred subjects underwent amyloid positron emission tomography (PET) imaging with [ ¹⁸ F]-flutemetamol and str...

Background: . High-quality comprehensive data on short-/long-term physical/mental health effects of the COVID�19 pandemic are needed. Methods: . The Collaborative Outcomes study on Health and Functioning during Infection Times (COH-FIT) is an international, multi-language (n=30) project involving >230 investigators from 49 countries/territories/r...

Background: Obesity is a frequent somatic comorbidity of major depression, and it has been associated with worse clinical outcomes and brain structural abnormalities. Converging evidence suggests that electroconvulsive therapy (ECT) induces both clinical improvements and increased subcortical grey matter volume in patients with depression. However...

Introduction: The COVID-19 pandemic has had a profound impact on the mental health of people around the world. Anxiety related to infection, stress and stigma caused by the forced changes in daily life have reportedly increased the incidence and symptoms of depression, anxiety disorder and obsessive-compulsive disorder. Under such circumstances, te...

Background: Electroconvulsive therapy (ECT) applies electric currents to the brain to induce seizures for therapeutic purposes. ECT increases gray matter (GM) volume, predominantly in the medial temporal lobe (MTL). The contribution of induced seizures to this volume change remains unclear. Methods: T1-weighted structural MRI was acquired from t...

Background There is growing evidence regarding the connection between alterations in gut microbiota and their metabolites in patients with depressive disorders, suggesting a potential role in pathophysiology. Our study aimed to investigate the relationship between microbial, metabolomic features and the course of treatment for depression in a real-...

Background Electroconvulsive therapy (ECT) applies electric currents to the brain to induce seizures for therapeutic purposes. ECT increases gray matter (GM) volume, predominantly in the medial temporal lobe (MTL). The contribution of induced seizures to this volume change remains unclear. Methods T1-weighted structural MRI was acquired from thirt...

Objective: Electroconvulsive therapy (ECT) is provided in real-world clinical settings for patients lacking capacity for consent. The aim of this study was to investigate the clinical characteristics and clinical effectiveness of ECT in this population. Methods: A retrospective chart review was conducted to collect data from patients who receive...

Late-life depression (LLD) is associated with a risk of developing Alzheimer's disease (AD). However, the role of AD-pathophysiology in LLD, and its association with clinical symptoms and cognitive function are elusive. In this study, one hundred subjects underwent amyloid positron emission tomography (PET) imaging with [18F]-flutemetamol and struc...

Background Electroconvulsive therapy (ECT) is the most effective treatment for severe depression. Recent neuroimaging studies have consistently reported that ECT induces volume increases in widely distributed brain regions. However, it still remains unclear about ECT-induced volume changes associated with clinical improvement. Methods Longitudinal...

Background Depression is associated with a risk of developing dementia and is hypothesized to enhance (pathological) brain aging. Previously we reported that amyloid burden in late‐life depression (LLD) did not differ from healthy controls in cortical regions typically associated with Alzheimer’s disease (AD) [1]. Here we extend our analysis beyond...

Recent genome-wide association studies have demonstrated that the genetic burden associated with depression correlates with depression severity. Therefore, conducting genetic studies of patients at the most severe end of the depressive disorder spectrum, those with treatment-resistant depression and who are prescribed electroconvulsive therapy (ECT...

Background Electroconvulsive therapy (ECT) is a well‐established treatment for psychiatric disorders, including depression and psychosis. ECT has been reported to be effective in treating such psychiatric symptoms in patients with Parkinson's disease (PD) and has been also reported to be effective in treating motor symptoms. The aim of the study is...

Background There are no reliable and validated objective biomarkers for the assessment of depression severity. We aimed to investigate the association between depression severity and timing-related speech features using speech recognition technology. Method Patients with major depressive disorder (MDD), those with bipolar disorder (BP), and health...

Introduction Depressive and neurocognitive disorders are debilitating conditions that account for the leading causes of years lived with disability worldwide. However, there are no biomarkers that are objective or easy-to-obtain in daily clinical practice, which leads to difficulties in assessing treatment response and developing new drugs. New tec...

Loss of cognitive ability is commonly associated with dementia, a broad category of progressive brain diseases.~However, major depressive disorder may also cause temporary deterioration of one’s cognition known as pseudodementia.~Differentiating a true dementia and pseudodementia is still difficult even for an experienced clinician and extensive an...

Background Electroconvulsive therapy (ECT) is the most effective antidepressant treatment for severe depression. Although recent structural magnetic resonance imaging (MRI) studies have consistently reported ECT-induced hippocampal volume increases, most studies did not find the association of the hippocampal volume changes with clinical improvemen...

Objective: We aimed to develop a machine learning algorithm to screen for depression and assess severity based on data from wearable devices. Methods: We used a wearable device that calculates steps, energy expenditure, body movement, sleep time, heart rate, skin temperature, and ultraviolet light exposure. Depressed patients and healthy volunte...

Objective: To identify important clinical or imaging features predictive of an individual's response to electroconvulsive therapy (ECT) by utilizing a machine learning approach. Methods: Twenty-seven depressed patients who received ECT were recruited. Clinical demographics and pretreatment structural magnetic resonance imaging (MRI) data were us...

Background: Depressive and neurocognitive disorders are debilitating conditions that account for the leading causes of years lived with disability worldwide. Overcoming these disorders is an extremely important public health problem today. However, there are no biomarkers that are objective or easy-to-obtain in daily clinical practice, which leads...

Recent longitudinal neuroimaging studies in patients with electroconvulsive therapy (ECT) suggest local effects of electric stimulation (lateralized) occur in tandem with global seizure activity (generalized). We used electric field (EF) modeling in 151 ECT treated patients with depression to determine the regional relationships between EF, unbiase...

Microstructural white matter (WM) disruption and resulting abnormal structural connectivity form a potential underlying pathology in traumatic brain injury (TBI). Herein, to determine the potential mechanism of cognitive deterioration in TBI, we examined the association of damage to specific WM tracts with cognitive function in TBI patients. We rec...

Electroconvulsive therapy (ECT) is the most effective antidepressant treatment. Biological predictors of clinical outcome to ECT are valuable. We aimed to examine multimodal magnetic resonance imaging (MRI) data that correlates to the efficacy of ECT. Structural and resting-state functional MRI data were acquired from 46 individuals (25 depressed i...

Background: Electroconvulsive therapy (ECT) is associated with volumetric enlargements of corticolimbic brain regions. However, the pattern of whole-brain structural alterations following ECT remains unresolved. Here, we examined the longitudinal effects of ECT on global and local variations in gray matter, white matter, and ventricle volumes in p...

Background: Actigraphy has enabled consecutive observation of individual health conditions such as sleep or daily activity. This study aimed to examine the usefulness of actigraphy in evaluating depressive and/or bipolar disorder symptoms. Method: A systematic review and meta-analysis was conducted. We selected studies that used actigraphy to co...

Introduction: Electroconvulsive therapy (ECT) has antidepressant effects, but it also has possible cognitive side effects. The effects of ECT on neuronal oscillatory pattern and phase synchronization, and the relationship between clinical response or cognitive change and electroencephalogram (EEG) measurements remain elusive. Methods: Individuals w...

Objective: We aimed to examine attitudes toward electroconvulsive therapy (ECT) among involuntary patients, voluntary patients, and their relatives. Methods: Patients experiencing a major depressive episode and receiving ECT and their relatives were recruited for the survey. Patients and their relatives answered the self-rating questionnaires wi...

Electroconvulsive therapy (ECT) is the most effective treatment for severe depression, although the underlying mechanisms remain unclear. Animal studies have consistently shown that electroconvulsive stimulation induces neuroplastic changes in the dentate gyrus. To date, few studies have investigated the effect of ECT on human hippocampal subfields...

Diagnosis of psychiatric disorders is based primarily on subjective symptoms, and neuroimaging or other biological examinations are used for excluding organic disorders. Advances in artificial intelligence technologies, such as machine learning, may enable us to utilize neuroimaging for individual diagnosis of psychiatric disorder or treatment resp...

Alterations in glutamatergic neurotransmission are implicated in the pathophysiology of depression, and the glutamatergic system represents a treatment target for depression. To summarize the nature of glutamatergic alterations in patients with depression, we conducted a meta-analysis of proton magnetic resonance (1H-MRS) spectroscopy studies exami...

Background Electroconvulsive therapy (ECT) is one of the most effective treatments for depression, although the underlying mechanisms remain unclear. Animal studies have shown that electroconvulsive shock induced neuroplastic changes in the hippocampus. Aims To summarise volumetric magnetic resonance imaging studies investigating the effects of EC...

This poster was presented in the 2nd international Brain Stimulation conference.

This study was published in the Journal of Psychiatry.

Linear fitting and Integral mode. First, we calculated the linear function (base curve) between the pre- and post-task baseline average. This inclination of linear function was thought to originate from NIRS signal fluctuations. We then subtracted the base curve from the original data (linear fitting), to derive integral data for further analysis.

Baseline characteristics of the standard or low-dose groups (??1 antidepressant DDD) and high-dose group (>?1 antidepressant DDD) in MDD.

Centroid value. The centroid value represents timing of the frontal NIRS signal, and is indicated by time shown with a perpendicular line.

Scatter graph showing the relationship between antidepressant DDD and frontal centroid value in participants with MDD. Twenty-one (63.6%) participants had FCV responses?>?54.0?s (indicating schizophrenia or bipolar disorder) and 12 (36.4%) participants had responses? ?54.0?s) (odds ratio: 8.25; 95% CI: 0.89?76.2).

Factors associated with [oxy-Hb] value in each channel.

Background Recent studies have highlighted the clinical usefulness of near-infrared spectroscopy (NIRS) in psychiatry. However, the potential effects of psychotropics on NIRS signals remain unknown. Methods We conducted a systematic chart review of 40 depressed patients who underwent NIRS scans during a verbal fluency task to clarify the relations...

While the efficacy and tolerability of electroconvulsive therapy (ECT) for depression has been well established, the acute effects of ECT on brain function remain unclear. Particularly, although cognitive dysfunction has been consistently observed after ECT, little is known about the extent and time course of ECT-induced brain functional changes, a...

High-frequency left prefrontal repetitive transcranial magnetic stimulation (rTMS) has been shown to have efficacy in treatment-resistant depression. However, the effects of rTMS on functional connectivity are still not clear. To examine changes in functional connectivity before and after rTMS, resting EEG of 14 patients with treatment-resistant de...