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Objective Accumulated evidence collected via functional near-infrared spectroscopy (fNIRS) has been reported with regard to mental disorders. A previous finding revealed that emotional words evoke left frontal cortex activity in patients with depression. The primary aim of the current study was to replicate this finding using an independent dataset and evaluate the brain region associated with the severity of depression using an emotional Stroop task. Methods Oxygenized and deoxygenized hemoglobin recording in the brain by fNIRS on 14 MDD patients and 20 normal controls. Results Hyperactivated oxygenized hemoglobin was observed in the left frontal cortex on exposure to unfavorable stimuli, but no significant difference was found among patients with depression compared with healthy controls on exposure to favorable stimuli. This result is consistent with previous findings. Moreover, an evoked wave associated with the left upper frontal cortex on favorable stimuli was inversely correlated with the severity of depression. Conclusion Our current work using fNIRS provides a potential clue regarding the location of depression symptom severity in the left upper frontal cortex. Future studies should verify our findings and expand them into a precise etiology of depression.

To clarify the risk factors for suicide among university students, we collected the data of students who died of any cause from 1992 to 2017 from the accident records of the Yamaguchi University. Sociodemographic and clinical data from the health examination and medical records of the university were examined. Chi-squared analysis was used. Of the 93 students who died, 48 were suicide cases over 26 years. Overall suicide rate was 17.4/100,000 persons. No longitudinally significant difference in suicide rate was seen between the same-age population (1998-2017; 20.0) and the university students. Higher risk of suicide in students was seen among males (odds ratio [OR] =3.5, 95% confidence interval [CI]=1.49-8.22; 1992-2017), those who did not undertake a health examination in the year when they died by suicide (OR =5.82, 95% CI =2.41-14.04), and those who had usage history in the center for mental health consultations (OR =23.29, 95% CI =9.03-60.07) from 2006 to 2017. Characteristic risk factor was that they had undergone no health examination, representing unfavorable attitudes towards seeking help. We propose that the annual health examination should be used as a place for creating awareness for mental health problems.

Although literature evidence suggests deficits in social and non-social cognition in patients with autistic spectrum disorder (ASD) and schizophrenia (SCZ), the difference in neural correlates of the impairments between the two disorders has not been elucidated. We examined brain function in response to a non-social cognition and a social cognition task using functional near-infrared spectroscopy (fNIRS) in 13 patients with ASD, 15 patients with SCZ, and 18 healthy subjects. We assessed the brain function of participants using a verbal fluency task and an emotional facial recognition task. The patients with ASD showed significantly reduced brain activation in the left frontotemporal area during both tasks compared to healthy subjects. The patients with ASD with larger score in ‘attention to detail’ in the autism spectrum quotient showed lower activation of the left frontotemporal area during the two tasks. The patients with SCZ showed significantly reduced activation, compared to healthy subjects, and greater activation, compared to patients with ASD, in the area during the verbal fluency task. The patients with SCZ with more severe symptoms had lower brain activation during the task in this area. Our results suggest that two distinct areas are involved in the distinctive brain pathophysiology relevant to cognitive processing in patients with ASD and SCZ.

Background Depression in old age is an increasing contributor to poor health and accompanying health care costs. Although there is an abundance of literature on later-life depression (LLD), the neural correlates have not been clarified. The aim of this study was to determine whether patients with LLD show abnormal gray matter volume (GMV) and white matter integrity by using multiple image analysis methods. Methods The study included 45 patients with LLD and 61 healthy participants who were matched for age, sex, years of education, and vascular risk factors. GMV was examined using voxel-based morphometry, while the white matter integrity was determined by tract-based spatial statistics and tract-specific analysis, which were obtained from high-resolution magnetic resonance images. Results Patients with LLD showed significantly less GMV in the orbitofrontal cortex, anterior cingulate, insula, amygdala, and temporal regions, as well as higher fractional anisotropy in the uncinate fasciculus, compared with healthy participants. Patients with LLD who had reduced orbitofrontal and insular GMV had more severe clinical variables. The reduced orbitofrontal GMV was associated with higher fractional anisotropy in the uncinate fasciculus. Limitation The effects of medication should also be considered when interpreting the results of this study. Conclusion Our results suggest that regional GMV is linked to white matter integrity of the uncinate fasciculus in the orbitomedial prefrontal limbic network, and the disruption of this network may be involved in the pathophysiology of LLD.

Although patients with schizophrenia demonstrate abnormal processing of emotional face recognition, the neural substrates underlying this process remain unclear. We previously showed abnormal fronto-temporal function during facial expression of emotions, and cognitive inhibition in patients with schizophrenia using functional near-infrared spectroscopy (fNIRS). The aim of the current study was to use fNIRS to identify which brain regions involved in recognizing emotional faces are impaired in patients with schizophrenia, and to determine the neural substrates underlying the response to emotional facial expressions per se, and to facial expressions with cognitive inhibition. We recruited 19 patients with schizophrenia and 19 healthy controls, statistically matched on age, sex, and premorbid IQ. Brain function was measured by fNIRS during emotional face assessment and face identification tasks. Patients with schizophrenia showed lower activation of the right precentral and inferior frontal areas during the emotional face task compared to controls. Further, patients with schizophrenia were slower and less accurate in completing tasks compared to healthy participants. Decreasing performance was associated with increasing severity of the disease. Our present and prior studies suggest that the impaired behavioral performance in schizophrenia is associated with different mechanisms for processing emotional facial expressions versus facial expressions combined with cognitive inhibition.

Patients with later-life depression (LLD) show abnormal gray matter (GM) volume, white matter (WM) integrity and functional connectivity in the anterior cingulate cortex (ACC) and posterior superior temporal gyrus (pSTG), but it remains unclear whether these abnormalities persist over time. We examined whether structural and functional abnormalities in these two regions are present within the same subjects during depressed vs. remitted phases. Sixteen patients with LLD and 30 healthy subjects were studied over a period of 1.5 years. Brain images obtained with a 3-Tesla magnetic resonance imaging (MRI) system were analyzed by voxel-based morphometry of the GM volume, and diffusion tensor imaging (DTI) and resting-state functional MRI were used to assess ACC-pSTG connectivity. Patients with LLD in the depressed and remitted phases showed significantly smaller GM volume in the left ACC and left pSTG than healthy subjects. Both patients with LLD in the depressed and remitted phases had significantly higher diffusivities in the WM tract of the left ACC-pSTG than healthy subjects. Remitted patients with LLD showed lower functional ACC-pSTG connectivity compared to healthy subjects. No difference was found in the two regions between depressed and remitted patients in GM volume, structural or functional connectivity. Functional ACC-pSTG connectivity was positively correlated with lower global function during remission. Our preliminary data show that structural and functional abnormalities of the ACC and pSTG occur during LLD remission. Our findings tentatively reveal the brain pathophysiology involved in LLD and may aid in developing neuroanatomical biomarkers for this condition.

Little is known about disorder-specific biomarkers of bipolar disorder (BD) and major depressive disorder (MDD). Our aim was to determine a neural substrate that could be used to distinguish BD from MDD. Our study included a BD group (10 patients with BD, 10 first-degree relatives (FDRs) of individuals with BD), MDD group (17 patients with MDD, 17 FDRs of individuals with MDD), and 27 healthy individuals. Structural and functional brain abnormalities were evaluated by voxel-based morphometry and a trail making test (TMT), respectively. The BD group showed a significant main effect of diagnosis in the gray matter (GM) volume of the anterior cingulate cortex (ACC; p = 0.01) and left insula (p < 0.01). FDRs of individuals with BD showed significantly smaller left ACC GM volume than healthy subjects (p < 0.01), and patients with BD showed significantly smaller ACC (p < 0.01) and left insular GM volume (p < 0.01) than healthy subjects. The MDD group showed a tendency toward a main effect of diagnosis in the right and left insular GM volume. The BD group showed a significantly inverse correlation between the left insular GM volume and TMT-A scores (p < 0.05). Our results suggest that the ACC volume could be a distinct endophenotype of BD, while the insular volume could be a shared BD and MDD endophenotype. Moreover, the insula could be associated with cognitive decline and poor outcome in BD.