Takahiro Nemoto
Toho University
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Featured researches published by Takahiro Nemoto.
Australian and New Zealand Journal of Psychiatry | 2008
Ryoko Yamazawa; Takahiro Nemoto; Hiroyuki Kobayashi; Bun Chino; Masafumi Mizuno
Objective: The aim of the present study was to identify the relationship between duration of untreated psychosis (DUP), premorbid functioning, and cognitive dysfunction and the outcome of first-episode schizophrenia. Method: Thirty-four neuroleptic-naïve patients who consulted hospitals in Tokyo and who were treated by psychiatrists for the first time were evaluated with regard to DUP, premorbid functioning, psychiatric symptoms, and global functioning. The neuropsychological test battery consisted of the Letter Cancellation Test, Trail-Making Test, Digit Span and Verbal Fluency Test. One year later, 24 of the subjects were reassessed for psychiatric symptoms, global functioning, and social functioning, and the relationships between DUP, premorbid functioning, and cognitive performance and the outcome was investigated. Results: Short DUP, good premorbid functioning, and good Letter Cancellation Test, Digit Span and Verbal Fluency Test scores were significantly associated with good outcome. Conclusions: The present results in a Japanese sample are consistent with previous international evidence that delay of initial treatment, premorbid functioning, and cognitive deficits are associated with outcome. A major limitation of the present study was the small size of the subject group. But because the subjects were relatively homogeneous and not influenced by psychoactive substances, the results reflect the essence of the disorder.
Early Intervention in Psychiatry | 2009
Masafumi Mizuno; Michio Suzuki; Kazunori Matsumoto; Masaaki Murakami; Kiyoaki Takeshi; Tetsuo Miyakoshi; Fumiaki Ito; Ryoko Yamazawa; Hiroyuki Kobayashi; Takahiro Nemoto; Masayoshi Kurachi
Aim: To describe clinical practice and research activities for early psychiatric intervention in Japan, a country with a huge number of psychiatric beds and a history of long‐stay, hospital‐based psychiatry.
Schizophrenia Research | 2011
Hiroyuki Kobayashi; Takahiro Nemoto; Masaaki Murakami; Masafumi Mizuno
BACKGROUNDS It still remains unclear whether individuals who experience attenuated psychotic symptoms are likely to seek help, whereas depressive symptoms are more likely to be associated with help-seeking behavior than these symptoms themselves. The aims of our study were to compare the profile of these symptoms between clinical and community samples and to investigate to what extent help-seeking behavior depends on the severity of psychosis-like symptoms and/or depressive symptoms. METHODS The clinical sample consisted of help-seeking outpatients aged 16-30 years who had approached a community mental health clinic (N=750, mean age: 23.3±4.2 years, 62.4% females). The community sample was comprised of students from two universities and two high schools (N=781, mean age: 18.1±1.7 years, 59.2% females). Psychosis-like experiences were assessed using the PRIME Screen-Revised (PS-R), a self-reported screening instrument for assessing the risk of psychosis. Depressive symptoms were assessed using the Zung Self-rating Depression Scale (ZSDS), a 20-item self-reported questionnaire. RESULTS Among the clinical and community samples, 27% and 10% had positive PS-R results respectively. No significant difference in the PS-R total score or the frequency of PS-R-positive items was observed between the clinical and community samples. A logistic regression analysis revealed that none of the psychosis-like experiences were significantly associated with help-seeking behavior, after controlling for the effect of depressive symptoms. CONCLUSIONS Our findings showed that attenuated psychotic symptoms do not contribute significantly to help-seeking behavior, suggesting that the relationships among PLEs, depressive symptoms, and help-seeking behavior should be reconsidered.
Progress in Neuro-psychopharmacology & Biological Psychiatry | 2010
Kiyoaki Takeshi; Takahiro Nemoto; Masaki Fumoto; Hideho Arita; Masafumi Mizuno
Relationships between deficits in verbal fluency and poor social functioning have been revealed in patients with schizophrenia. In previous studies, we demonstrated that deficits in idea fluency, which is ranked as a more complex type of verbal fluency and reflects divergent thinking ability, were more closely related to social dysfunction than deficits in simple word fluency. Although functional neuroimaging studies have provided detailed data regarding prefrontal dysfunction during word fluency tasks, the regions that relate to deficits in fluency of ideas and thoughts have not yet been clarified in schizophrenia patients. The purpose of the present study was to identify the prefrontal sub-regions responsible for deficits in idea fluency using near-infrared spectroscopy (NIRS), which is more practical than other imaging methods, and to investigate the relationships between lesions and idea fluency deficits and social dysfunction in patients with schizophrenia. Eighteen outpatients with schizophrenia and 16 healthy subjects were recruited for this case-controlled study. Using 24-channel NIRS, we measured changes in hemoglobin concentration in the prefrontal cortical surface area during idea and letter fluency tests. The analyses revealed that schizophrenia patients generally exhibited a smaller increase in the concentration of oxyhemoglobin in the frontopolar region than the controls during both the tests. However, the areas in which reduced activations were demonstrated in the patients differed remarkably between the idea and letter fluency tests: reduced activations were observed in the ventral region during the former test and in the dorsal region of the frontopolar cortex during the latter test. The reduced activations in each sub-region appeared to affect the related cognitive impairment, since the patients showed significant poorer performances than the controls on both the tests. Moreover, hypoactivity during idea fluency was significantly correlated with poor social functioning as assessed using the Global Assessment of Functioning (GAF) in the patient group. The results of the present study suggest that the ventral region within the frontopolar cortex is responsible for divergent thinking, which is associated with poor social functioning in patients with schizophrenia.
European Psychiatry | 2015
Shinya Ito; Takahiro Nemoto; Naohisa Tsujino; Noriyuki Ohmuro; Kazunori Matsumoto; Hiroo Matsuoka; Kodai Tanaka; Shimako Nishiyama; Michio Suzuki; H. Kinoshita; H. Ozawa; H. Fujita; S. Shimodera; Toshifumi Kishimoto; T. Hasegawa; Masafumi Mizuno
BACKGROUND The mode of onset and the course of schizophrenia illness exhibit substantial individual variations. Previous studies have pointed out that the mode of onset affects the duration of untreated psychosis (DUP) and clinical outcomes, such as cognitive and social functioning. This study attempted to clarify the association between the DUP and clinical features, taking the different modes of onset into consideration, in a prospective longitudinal study examining patients with first-episode schizophrenia. METHODS This study was conducted in six areas of Japan. Patients with first-episode schizophrenia were followed for over 18 months. Cognitive function, psychopathology, and social functioning were assessed at baseline and at 6, 12, and 18-month follow-up points. RESULTS We identified 168 patients and sufficient information was available to determine the DUP and the mode of onset for 156 patients (92.9%): 79 had an acute onset, and 77 had an insidious onset. The DUP was significantly associated with quality of life (QOL), social functioning, and cognitive function at most of the follow-up points in the insidious-onset group. The DUP and negative symptoms at baseline were significant predictors of cognitive function at the 18-month follow-up in the insidious-onset group. CONCLUSIONS The present results further support the hypothesis that the DUP affects QOL, social functioning, and cognitive function over the course of illness, especially in patients with an insidious onset. Effective strategies for detecting and caring for individuals with insidious onset early during the course of schizophrenia will be essential for achieving a full patient recovery.
Psychiatry and Clinical Neurosciences | 2011
Naohisa Tsujino; Takahiro Nemoto; Taiju Yamaguchi; Naoyuki Katagiri; Nao Tohgi; Ryu Ikeda; Nobuyuki Shiraga; Sunao Mizumura; Masafumi Mizuno
The purpose of the present study was to investigate regional cerebral blood flow (rCBF) changes in a patient with very‐late‐onset schizophrenia‐like psychosis (VLOS) with catatonia. A 64‐year‐old woman developed catatonia after experiencing persecutory delusions. The patients rCBF was examined using single photon emission computed tomography (SPECT) with easy Z‐score imaging system. Before treatment, hypoperfusion was observed in the striatum and the thalamus, whereas hyperperfusion was observed in the left lateral frontal cortex and the left temporal cortex. After treatment, the disproportions in rCBF disappeared, and hyperperfusion was observed in the motor cortex. Sequential SPECT findings suggest that rCBF abnormalities may be correlated with the symptomatology of catatonia in patients with VLOS.
Schizophrenia Research | 2014
Takahiro Nemoto; Hidehito Niimura; Yonosuke Ryu; Kei Sakuma; Masafumi Mizuno
Schizophrenia is associated with impairments in social interactions, and the conditions under which patients live and undergo treatment appear to have an important role in the course of the disease. However, the influences of care settings on the course of cognition remain controversial. The closure of psychiatric hospitals and the transition to community-based living is a golden opportunity to address this issue. The aims of the present study were to examine (1) the longitudinal course of cognition as well as the psychopathology and social functioning of schizophrenia patients who had been chronically hospitalized and then discharged, and (2) the key cognitive predictors of the functional outcome of such patients. Seventy-eight patients were transferred to the community after the closure of a psychiatric hospital. These patients were followed-up for 5 years and underwent annual examinations that included measures of cognition, psychiatric symptoms, and social functioning. Fifty-six patients completed all the assessments. Although consistent improvements were shown in the cognitive domains for attention and memory, the initial improvements in global cognition and processing speed ultimately began to decline. Symptoms and global functioning improved almost consistently over the course of the follow-up period. Stepwise multiple regressions revealed category fluency at baseline predicted social functioning at 5 years. However, this correlation was no longer significant when psychopathological variables were included as predictors. These results suggest that care settings affect the course of cognition, and addressing these conditions may lead to a certain degree of cognitive improvement even among schizophrenia patients who have been chronically institutionalized.
Early Intervention in Psychiatry | 2014
Keiko Morita; Hiroyuki Kobayashi; Kiyoaki Takeshi; Naohisa Tsujino; Takahiro Nemoto; Masafumi Mizuno
It remains debatable whether early intervention for psychosis is capable of meeting the needs of at‐risk subjects. The aims of this study were to describe the actual impact of interventions on subjective difficulties and to explore the factors that may be associated with a poor outcome.
Early Intervention in Psychiatry | 2010
Hiroyuki Kobayashi; Ryoko Yamazawa; Takahiro Nemoto; Masaaki Murakami; Masafumi Mizuno
Aims: To examine the emergence of attenuated psychotic experiences, self‐disturbance or affective symptoms among younger subjects in the general population and to investigate the intergroup differences on each symptom between adolescents and post‐adolescents.
Comprehensive Psychiatry | 2016
Miki Tobe; Takahiro Nemoto; Naohisa Tsujino; Taiju Yamaguchi; Naoyuki Katagiri; Chiyo Fujii; Masafumi Mizuno
BACKGROUND Deficits of motivation have been considered to be a core feature of schizophrenia, and recent studies have begun to reveal the biological and psychological characteristics and mechanisms underlying the deficits in motivation in schizophrenia patients. The aims of the present study were to investigate the characteristics of motivation in schizophrenia patients using the General Causality Orientations Scale (GCOS), and the impacts of motivational orientations on the functional outcomes in schizophrenia patients. METHODS A total of 53 outpatients with schizophrenia and 38 healthy controls were recruited for this study. The GCOS was used to assess individual tendencies in respect of three different motivational orientations: the autonomy, controlled, and impersonal orientations, corresponding to intrinsic motivation, extrinsic motivation, and amotivation, respectively. The cognitive functioning, psychiatric symptoms, social functioning, and quality of life of the subjects were also assessed. RESULTS The score for autonomy orientation was significantly lower in the patient group than that in the control group, while no significant differences were found between the two groups in respect of the scores for the other two orientations. The autonomy orientation was associated with various clinical variables, and regression analysis identified as one of the variables with the highest predictive accuracy for social functioning. CONCLUSIONS Intrinsic motivation measured by the GCOS in schizophrenia patients was significantly lower than that in healthy controls. The deficits of intrinsic motivation were broadly associated with the clinical features and were a determinant of social functioning. Development of treatments for enhancing intrinsic motivation would be essential for functional recovery in schizophrenia patients.