Publications by authors named "Takashi Nakamae"

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 controlled trial to determine the effectiveness of long-term treatment for multiple psychiatric disorders via two-way video using smartphones and other devices, which are currently the primary means of telecommunication.

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Objective: Neuroimaging studies of obsessive-compulsive disorder (OCD) patients have highlighted the important role of deep gray matter structures. Less work has however focused on subcortical shape in OCD patients.

Methods: Here we pooled brain MRI scans from 412 OCD patients and 368 controls to perform a meta-analysis utilizing the ENIGMA-Shape protocol.

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Background: Widely used psychotropic medications for obsessive-compulsive disorder (OCD) may change the volumes of subcortical brain structures, and differently in children vs. adults. We measured subcortical volumes cross-sectionally in patients finely stratified for age taking various common classes of OCD drugs.

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Larger thalamic volume has been found in children with obsessive-compulsive disorder (OCD) and children with clinical-level symptoms within the general population. Particular thalamic subregions may drive these differences. The ENIGMA-OCD working group conducted mega- and meta-analyses to study thalamic subregional volume in OCD across the lifespan.

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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, telepsychiatry is gaining importance and attracting a great deal of attention.

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Article Synopsis
  • A study investigated microstructural changes in brain connections related to obsessive-compulsive disorder (OCD) using a large sample of 700 adults and 174 pediatric patients.
  • The researchers found that adult OCD patients showed significant reductions in a measure of white matter integrity (fractional anisotropy) in specific brain areas, which were linked to factors like age of onset and illness duration.
  • In contrast, pediatric OCD patients did not show any notable microstructural differences when compared to controls, suggesting variations in the disorder's presentation across age groups.
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Aim: Obsessive-compulsive disorder (OCD) is a common and severe disease; however, the duration of untreated illness (DUI) of OCD is approximately 7 years, which is longer than that of other psychiatric disorders. Differences in medical environments have been reported to affect the DUI. Therefore, we surveyed the DUI of OCD in Japan and the reason for delayed treatment.

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Article Synopsis
  • Scientists want to find ways to diagnose obsessive-compulsive disorder (OCD) using brain scans, but so far, there are no good tests.
  • They studied a lot of data from almost 2,300 OCD patients and over 2,000 healthy people using special MRI scans.
  • They discovered that the brain's differences could show up based on whether patients took medication, which made it harder to use these scans as a reliable way to understand OCD.
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Article Synopsis
  • - Large-scale neuroimaging studies show differences in cortical thickness in various psychiatric disorders, but the biological reasons for these differences are not fully understood.
  • - The study aimed to identify neurobiological correlates of cortical thickness variations between affected individuals and controls across six disorders: ADHD, ASD, BD, MDD, OCD, and schizophrenia.
  • - Using data from 145 cohorts and advanced imaging techniques, the analysis revealed distinct patterns of cortical thickness associated with specific gene expressions in disorders, involving a total of over 28,000 participants.
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  • The study compares ADHD, ASD, and OCD using brain imaging data from over 5,000 healthy controls and numerous patients across different age groups, focusing on structural differences in the brain.
  • No consistent differences were observed across all three disorders, with some specific findings like smaller hippocampal volumes in children with ADHD compared to OCD.
  • The results highlight that while subtle differences exist between these disorders, the distinctions are most apparent in specific age groups, emphasizing ADHD's unique brain volume differences in younger individuals and ASD's cortical thickness variations in adults.
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Neuroimaging has played an important part in advancing our understanding of the neurobiology of obsessive-compulsive disorder (OCD). At the same time, neuroimaging studies of OCD have had notable limitations, including reliance on relatively small samples. International collaborative efforts to increase statistical power by combining samples from across sites have been bolstered by the ENIGMA consortium; this provides specific technical expertise for conducting multi-site analyses, as well as access to a collaborative community of neuroimaging scientists.

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Brain structural covariance networks reflect covariation in morphology of different brain areas and are thought to reflect common trajectories in brain development and maturation. Large-scale investigation of structural covariance networks in obsessive-compulsive disorder (OCD) may provide clues to the pathophysiology of this neurodevelopmental disorder. Using T1-weighted MRI scans acquired from 1616 individuals with OCD and 1463 healthy controls across 37 datasets participating in the ENIGMA-OCD Working Group, we calculated intra-individual brain structural covariance networks (using the bilaterally-averaged values of 33 cortical surface areas, 33 cortical thickness values, and six subcortical volumes), in which edge weights were proportional to the similarity between two brain morphological features in terms of deviation from healthy controls (i.

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Article Synopsis
  • Scientists studied the brains of kids and adults with obsessive-compulsive disorder (OCD) to see if there are differences in brain structure on either side.
  • They looked at a lot of data from different patients and healthy people using special brain scans.
  • They found that kids with OCD had small differences in certain brain structures, but adults with OCD didn’t show these differences, which might mean kids’ brains develop differently when they have OCD.
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Brain imaging communities focusing on different diseases have increasingly started to collaborate and to pool data to perform well-powered meta- and mega-analyses. Some methodologists claim that a one-stage individual-participant data (IPD) mega-analysis can be superior to a two-stage aggregated data meta-analysis, since more detailed computations can be performed in a mega-analysis. Before definitive conclusions regarding the performance of either method can be drawn, it is necessary to critically evaluate the methodology of, and results obtained by, meta- and mega-analyses.

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Purpose: In recent years, a large number of studies have investigated obsessive-compulsive disorder (OCD) using diffusion-weighted images (DWIs) and have reported microstructural abnormalities in various regions, mainly the corpus callosum and cingulum. In the present study, we aimed to detect microstructural changes in the white matter using whole-brain tractography.

Patients And Methods: We obtained MRI data from 25 adult non-medicated OCD patients and 27 healthy controls.

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Objective: Impulsivity and impaired decision-making have been proposed as obsessive-compulsive disorder (OCD) endophenotypes, running in OCD and their healthy relatives independently of symptom severity and medication status. Deep brain stimulation (DBS) targeting the ventral limb of the internal capsule (vALIC) and the nucleus accumbens (Nacc) is an effective treatment strategy for treatment-refractory OCD. The effectiveness of vALIC-DBS for OCD has been linked to its effects on a frontostriatal network that is also implicated in reward, impulse control, and decision-making.

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Objective: Brain imaging studies of structural abnormalities in OCD have yielded inconsistent results, partly because of limited statistical power, clinical heterogeneity, and methodological differences. The authors conducted meta- and mega-analyses comprising the largest study of cortical morphometry in OCD ever undertaken.

Method: T-weighted MRI scans of 1,905 OCD patients and 1,760 healthy controls from 27 sites worldwide were processed locally using FreeSurfer to assess cortical thickness and surface area.

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Background: Many studies reported the high prevalence of problematic internet use (PIU) among adolescents (13-50%), and PIU was associated with various psychiatric symptoms. In contrast, only a few studies investigated the prevalence among the adult population (6%). This study aimed to investigate the prevalence of PIU and psychiatric co-morbidity among adult psychiatric patients.

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Obsessive-compulsive disorder (OCD) is a common psychiatric disorder with a lifetime prevalence of 2-3%. Recently, brain activity in the resting state is gathering attention for exploring altered functional connectivity in psychiatric disorders. Although previous resting-state functional magnetic resonance imaging studies investigated the neurobiological abnormalities of patients with OCD, there are concerns that should be addressed.

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Background: Burnout is a psychological condition that may occur after being exposed to excessive and prolonged work-related stresses. Previous studies have demonstrated that the rate of burnout among physicians may be higher compared to other occupations ; and espe- cially psychiatric trainees would have a higher risk of burnout because of limited clinical expe- rience, the burden of heavy duties and longer work-hours etc. In this study, we report the findings from Japanese data obtained as part of the international study of burnout syndrome among psychiatric trainees (BoSS International).

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The two hemispheres of the human brain differ functionally and structurally. Despite over a century of research, the extent to which brain asymmetry is influenced by sex, handedness, age, and genetic factors is still controversial. Here we present the largest ever analysis of subcortical brain asymmetries, in a harmonized multi-site study using meta-analysis methods.

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Objective: Structural brain imaging studies in obsessive-compulsive disorder (OCD) have produced inconsistent findings. This may be partially due to limited statistical power from relatively small samples and clinical heterogeneity related to variation in illness profile and developmental stage. To address these limitations, the authors conducted meta- and mega-analyses of data from OCD sites worldwide.

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Body integrity identity disorder (BIID) is a condition in which people do not perceive a part of their body as their own, which results in a strong desire for amputation or paralyzation. The disorder is likely to be congenital due to its very early onset. The English literature describes only Western patients with BIID, suggesting that the disorder might be merely prevalent in the West.

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