Tatsuro Ohta

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BACKGROUND AND PURPOSE To describe between-country differences in both the prevalence and type of sleep disorders seen across the globe, and to provide information on how impaired sleep impacts daytime functioning. PATIENTS AND METHODS The study is a large-scale, global cross-sectional survey conducted on International Sleep Well Day (March 21), 2002. A(More)
Alteration of tryptophan (TRP) metabolism elicited by proinflammatory cytokines has gained attention as a new concept to explain the etiological and pathophysiological mechanisms of major depression. The kynurenine (KYN) pathway, which is initiated by indoleamine 2,3-dioxygenase (IDO), is the main TRP metabolic pathway. It shares TRP with the serotonin(More)
Aging is a risk factor of human depression. Middle-aged or older men are vulnerable to adverse life events and an absence of social contact and easily become depressed. In the present study, we investigated the influence of aging on responses to life events in socially isolated conditions. We applied isolation-rearing (4 W) to two age groups, older (18 M)(More)
Isolation and acute environmental change are risk factors in human depression. In the present study, we investigated the differences in the brain monoamine activity of rats between two rearing conditions, isolated and group. Moreover, we examined the responses to novelty stress. Male F344 rats aged 11 weeks were divided into the above two groups. Four weeks(More)
Attention deficit-hyperactivity disorder (ADHD) has been noted for its high rate of comorbidity. The present study is the first report in Japan evaluating the proportion of comorbidity in ADHD cases presenting in the clinical setting, aiming at clarifying the picture of ADHD in Japan. The subjects consisted of 68 child and adolescent cases meeting criteria(More)
The purpose of this report is to introduce the potential of synchrotron radiation X-ray fluorescence (SRXRF) spectroscopy, by describing the application of this method to mapping and quantification of metallic elements in neurons from brain tissues affected by Alzheimer's disease (AD). In this study, clear images of Fe, Zn and Ca within certain single(More)
BACKGROUND In conversion disorder in childhood and adolescence, polysymptomatic (PS) presentations are reportedly commoner than monosymptomatic (MS) ones. Somatization disorder is also associated with pseudoneurological symptoms, but is extremely rare in childhood. This occurs despite the age of onset peaking in the teens among adult somatization disorder(More)
BACKGROUND In Asian countries, there is no epidemiological report on seasonal affective disorder (SAD) in different age groups and different geographic regions surveyed at the same time. The aim of this study was to estimate the prevalence rates of SAD and risk factors for SAD in adults and high-school students, with special reference to the difference of(More)
While it has long been recognized that certain hallucinations accompanying a high fever or epilepsy or appearing as a side effect of medication are common in childhood, it is only recently becoming clear that hallucinations may also occur as a feature of common psychiatric disorder without the unfavorable prognosis of childhood psychosis. The case described(More)