Publications by authors named "Motomu Suga"

An anomalous pattern of structural covariance has been reported in schizophrenia, which has been suggested to represent connectome changes during brain maturation and neuroprogressive processes. It remains unclear whether similar differences exist in a clinical high-risk state for psychosis, and if they are associated with a prodromal phenotype and/or later psychosis onset. This multicenter magnetic resonance imaging study cross-sectionally examined structural covariance in a large at-risk mental state (ARMS) sample with different outcomes.

View Article and Find Full Text PDF

Aim: Studies showed that cognitive function affects occupational function in patients with schizophrenia. This study aimed to determine the effects of cognitive function on occupational function in Japanese patients with schizophrenia using the Brief Assessment of Cognition in Schizophrenia (BACS).

Methods: Participants were 198 outpatients with schizophrenia or schizoaffective disorder (66 females; mean age 34.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates how changes in clinical symptoms relate to quality of life in individuals at ultra-high risk for psychosis and those with recent-onset psychotic disorders.
  • Researchers followed up with participants over a period ranging from 6 months to less than 5 years, assessing symptoms and quality of life using established measurement scales.
  • Results show that higher levels of anxiety/depression at the start were linked to poorer quality of life later, while improvements in these symptoms were associated with better quality of life outcomes.
View Article and Find Full Text PDF
Article Synopsis
  • Widespread cortical thinning in fronto-temporal regions has been noted in schizophrenia, but findings in those at risk for mental illness (ARMS) are inconsistent, raising questions about whether these abnormalities relate to functional decline regardless of future psychosis.
  • A study in Japan assessed 107 ARMS individuals compared to healthy controls using MRI to measure cortical thickness (CT), finding that ARMS individuals generally show reduced CT, especially in areas associated with cognitive function, and increased CT in other brain regions.
  • Non-resilient ARMS individuals displayed significantly reduced CT in the right paracentral lobule compared to resilient ones, suggesting that certain CT abnormalities may indicate a general vulnerability to mental illness and could serve as a biomarker for predicting
View Article and Find Full Text PDF
Article Synopsis
  • This study focused on individuals identified as ultra-high risk (UHR) for developing psychosis, aiming to find biomarkers that predict their prognosis, including remission and neurocognitive function.
  • Participants included 24 UHR individuals and 18 healthy controls, with mismatch negativity (MMN) measured through auditory tasks, assessing differences in their brain responses.
  • Results indicated that UHR individuals showed poorer MMN responses compared to controls, and those with larger dMMN amplitudes were more likely to achieve remission and display better cognitive functioning after six months.
View Article and Find Full Text PDF

Aim: Utena's Brief Objective Measures (UBOM) was developed to assess psychophysiological functions proximal to real-world functioning in individuals with psychiatric disorders, including schizophrenia (SCZ), to facilitate shared decision-making. However, the validity of UBOM has not been fully examined.

Methods: We conducted a cross-sectional observational study to evaluate the validity of each of the three tests in UBOM: UBOM-Pulse, UBOM-Ruler, and UBOM-Random.

View Article and Find Full Text PDF
Article Synopsis
  • - Previous research highlighted that both glutamatergic and GABAergic dysfunctions play roles in schizophrenia, indicating a disrupted balance of excitatory and inhibitory signals in the brain.
  • - A study involving participants with recent-onset schizophrenia, ultra-high risk individuals, and healthy controls found significant impairments in mismatch negativity (MMN) and gamma-band auditory steady-state response (ASSR) in those with schizophrenia and at ultra-high risk.
  • - The results showed a notable correlation between MMN and gamma-band ASSR in individuals with recent-onset schizophrenia, suggesting a potential link between NMDAR and GABA dysfunctions during the early stages of psychosis.
View Article and Find Full Text PDF
Article Synopsis
  • The study investigates the gamma-band auditory steady-state response (ASSR) as a potential biomarker for predicting long-term outcomes in early psychosis, particularly in patients with recent-onset schizophrenia and ultra-high risk individuals.
  • It found that both groups exhibited reduced gamma-band ASSR levels, and this reduction was linked to future symptoms in recent-onset schizophrenia patients.
  • The findings suggest that measuring gamma-band ASSR could be useful for forecasting the symptomatic progression of early psychosis, indicating its potential as a long-term prognosis biomarker.
View Article and Find Full Text PDF

Background: For patients starting treatment for depression, current guidelines recommend titrating the antidepressant dosage to the maximum of the licenced range if tolerated. When patients do not achieve remission within several weeks, recommendations include adding or switching to another antidepressant. However, the relative merits of these guideline strategies remain unestablished.

View Article and Find Full Text PDF

Objective: Uncovering molecular bases for auditory language processing in the human brain is a fundamental scientific challenge. The power and latency of the magnetic mismatch field (MMF) elicited by phoneme change, which are magnetoencephalographic indices of language function in its early stage of information processing, are theoretically thought to be modulated by N-methyl-d-aspartate-type glutamate receptor (NMDAR) function, but no study has yet assessed this possibility. We have thus sought to demonstrate an association between phonetic MMF power/latency and levels of plasma d-serine, an intrinsic co-agonist of glycine binding sites on NMDAR, in adults.

View Article and Find Full Text PDF
Article Synopsis
  • Mismatch negativity (MMN) is a potential early biomarker for psychosis, and while previous studies focused on chronic schizophrenia, this research examines its impact in early psychosis stages.
  • The study involves 76 participants, including individuals with recent-onset schizophrenia, those at ultra-high risk, and healthy controls, and assesses the relationships between different MMN types (deviant and frequency), cognitive functions, and overall functioning.
  • Results show that impaired deviant MMN correlates with lower global functioning in early-stage psychosis, underscoring its potential as a biological marker to inform treatment strategies.
View Article and Find Full Text PDF

Cognitive function is impaired in patients with schizophrenia-spectrum disorders, even in their prodromal stages. Specifically, the assessment of cognitive abilities related to daily-living functioning, or functional capacity, is important to predict long-term outcome. In this study, we sought to determine the validity of the Schizophrenia Cognition Rating Scale (SCoRS) Japanese version, an interview-based measure of cognition relevant to functional capacity (i.

View Article and Find Full Text PDF

Reduced amplitude of mismatch negativity (MMN) is one of the more promising biological markers of schizophrenia. This finding holds true in both early and chronic phases of the disorder, and is compatible with the glutamatergic dysfunction hypothesis. To further establish MMN as a biomarker of aberrant glutamatergic neurotransmission, an exploration for an association with blood levels of glutamatergic amino acids is an important next step.

View Article and Find Full Text PDF

The auditory mismatch negativity (MMN) is a component of event-related potentials, which is being increasingly recognized as a candidate biomarker for early stages of psychosis. Although previous cross-sectional studies have demonstrated small MMN amplitude in early stages of psychosis, it remains unknown whether small MMN amplitude is due to progressive reduction during the early course. In this study, we investigated longitudinal changes of MMN in early stages of psychosis.

View Article and Find Full Text PDF

Aim: There is an increasing need for identifying neurocognitive predictors of global functional outcome in early psychosis toward optimizing an early intervention strategy.

Methods: We conducted a longitudinal observational study to investigate an association between neurocognitive assessments at baseline and global functional outcome at an average of 1-year follow up. Participants included ultra-high-risk for psychosis (UHR) individuals who had not converted to psychosis during the follow-up period (UHR-NP) and those with first-episode psychosis (FEP).

View Article and Find Full Text PDF
Article Synopsis
  • * The study involved 33 pairs of monozygotic (MZ) and 10 pairs of dizygotic (DZ) twins, measuring MMNm responses to various auditory changes and correlating these with plasma amino acid levels related to glutamatergic neurotransmission.
  • * Results indicated a strong familial connection in MMNm strength among twins, with MZ twins showing correlations between MMNm latency differences and plasma amino acid levels, though the findings require further verification due to lack of significance after adjustment for multiple comparisons. *
View Article and Find Full Text PDF

Aim: Auditory mismatch negativity (MMN) and its magnetoencephalographic (MEG) counterpart (MMNm) are an established biological index in schizophrenia research. MMN in response to duration and frequency deviants may have differential relevance to the pathophysiology and clinical stages of schizophrenia. MEG has advantage in that it almost purely detects MMNm arising from the auditory cortex.

View Article and Find Full Text PDF

Recent studies have suggested that functional abnormalities in Broca's area, which is important in language production (speech and thoughts before speech), play an important role in the pathophysiology of schizophrenia. While multi-modal approaches have proved useful in revealing the specific pathophysiology of psychosis, the association of functional abnormalities with gray matter volume (GMV) here in subjects with an ultra-high risk (UHR) of schizophrenia, those with first-episode schizophrenia (FES), and healthy controls has yet to be clarified. Therefore, the relationship between cortical activity measured using functional near-infrared spectroscopy (fNIRS) during a verbal fluency task, and GMV in the Broca's area assessed using a manual tracing in magnetic resonance imaging (MRI), which considers individual structural variation, was examined for 57 subjects (23 UHR/18 FES/16 controls).

View Article and Find Full Text PDF

The roles of university hospital psychiatric departments are: 1) the development and pro- vision of advanced psychiatric treatments unique to university hospitals, 2) the provision of psychiatric intervention models for patients with physical diseases, and 3)the provision of real- world environments for young psychiatrists to learn the principles and experience the practice of such innovative care. As for 1), our facility offers a hospitalization for examination program, which uses near-infrared spectroscopy as a biomarker useful for the auxiliary diagnosis of psy- chiatric disease and selection of the treatment method. University psychiatric departments also play a major role in neuropsychiatry, such as through the use of Epilepsy Monitoring Units (EMU) to differentiate between epilepsy and psychogenic non-epileptic seizures (PNES).

View Article and Find Full Text PDF

Alterations in gamma-band auditory steady-state response (ASSR) are the most robust finding of abnormal neural oscillations in patients with first-episode (FES) and chronic schizophrenia. Gamma-band ASSRs may indicate GABAergic interneuron dysfunction. Nevertheless, it is unknown whether abnormal gamma-band ASSRs are present before the onset of psychosis.

View Article and Find Full Text PDF