Faculty Bibliography

Human short-time perception shows diurnal variation. In general, short-time perception fluctuates in parallel with circadian clock parameters, while diurnal variation seems to be modulated by sleep deprivation per se. Functional imaging studies have reported that short-time perception recruits a neural network that includes subcortical structures, as well as cortical areas involving the prefrontal cortex (PFC). It has also been reported that the PFC is vulnerable to sleep deprivation, which has an influence on various cognitive functions. The present study is aimed at elucidating the influence of PFC vulnerability to sleep deprivation on short-time perception, using the optical imaging technique of functional near-infrared spectroscopy. Eighteen participants performed 10-s time production tasks before (at 21:00) and after (at 09:00) experimental nights both in sleep-controlled and sleep-deprived conditions in a 4-day laboratory-based crossover study. Compared to the sleep-controlled condition, one-night sleep deprivation induced a significant reduction in the produced time simultaneous with an increased hemodynamic response in the left PFC at 09:00. These results suggest that activation of the left PFC, which possibly reflects functional compensation under a sleep-deprived condition, is associated with alteration of short-time perception.

The aim of the present study was to investigate the development of, prediction of, protection against, and the course of psychological distress and well-being in a sample of patients with motor vehicle accident-related injuries, in a cohort study. In a secondary analysis, the question of whether psychiatric morbidity was associated with quality of life in 95 injured patients after motor vehicle accident at 1-month follow up, was investigated. Results indicated that psychiatric morbidity has an adverse effect on quality of life.

BACKGROUND: The Tachikawa cohort of motor vehicle accident (TCOM) Study has been carried out in Tokyo since 2004. This study examined the association of medical and psychosocial variables evaluated shortly after admission to the acute critical care center with long-term psychiatric morbidity risk in patients with accidental injuries. METHODS: Between May 2004 and January 2008, patients with accidental injury consecutively admitted were recruited to the TCOM Study. Psychiatric morbidity as a primary endpoint was measured using a structured clinical interview at 1, 6, 18 and 36 months after involvement in a motor vehicle accident (MVA). The baseline investigation consisted of self-administered questionnaires concerning acute psychological responses and personality. Medical information was obtained from patients' medical charts. Various socio-demographic data, health-related habits and psychosocial factors were assessed by interview. To examine potential biomarkers of psychological distress, blood samples were collected. RESULTS: Out of 344 patients who were asked to participate in this study, 300 (87%) patients with MVA-related injury were enrolled. Corresponding rates for the questionnaires on psychological responses and blood sampling were 98-99 and 79%, respectively. The cohort sample was composed of 78% men; the median age was 34 years; and 45% of the participants were motorcycle drivers. CONCLUSIONS: The TCOM Study should prove useful for researchers examining the association between bio-psychosocial variables and psychological distress and may contribute to the formation of a framework for providing care for patients with MVA-related injury.

OBJECTIVE: To assess the reliability and validity of the Japanese version of the Peritraumatic Distress Inventory (PDI). METHOD: One hundred thirty-five participants with physical injury resulting from motor vehicle accidents were consecutively recruited in this cross-sectional study, from Aug. 18, 2005, to Jan. 8, 2008. A subsample (n=71) were retested on the PDI an average of 96.4 days after initial measure completion. RESULTS: Correlational analyses revealed an overall Cronbach's alpha coefficient of 0.83. The item-total correlations for the 13 items ranged from 0.29 to 0.75. The test-retest correlation coefficient was 0.61. The PDI was significantly correlated with the external validators such as peritraumatic dissociation as measured by the Peritraumatic Dissociative Experiences Questionnaire (PDEQ); the intrusion, avoidance and hyperarousal scores of the Impact of Events Scale-Revised (IES-R); and the depression and anxiety subscales of the Hospital Anxiety Depression Scale (HADS) (P<.01). CONCLUSION: The present study indicated that the Japanese version of the PDI has a high degree of internal consistency, acceptable reliability and a high degree of concurrent validity with measures of peritraumatic dissociation and posttraumatic symptoms. The Japanese version of the PDI can be used as a validated instrument in future research.

AIM: The present study was a 52-week, non-comparative, open-label study of flexible dose paroxetine (20-40 mg) in 52 Japanese post-traumatic stress disorder (PTSD) patients in order to obtain clinical experience regarding efficacy and safety in regular clinical practice. METHODS: Efficacy was measured using the Clinician-Administered PTSD Scale One Week Symptom Status Version (CAPS-SX). RESULTS: The mean change from baseline in CAPS-SX total score was -19.1, -22.8 and -32.3 at weeks 4, 12 and 52, respectively, and that in the Clinical Global Impression (CGI) Severity of Illness score was -1.1 at week 12 and -1.7 at week 52. A total of 46.9% were CGI responders at week 12, while 67.3% were improved on the CGI at week 52. Of 52 subjects who entered into the drug treatment, 25 completed the study. Only one patient withdrew from the study due to lack of efficacy. In patients who were rated as 'moderately ill' or less at baseline, the proportion of CGI responders at end-point was higher at a dose of 20 mg/day than at higher doses, whereas in patients rated as 'markedly ill' or more, it was higher at 30 and 40 mg/day, suggesting that severely ill patients could benefit from higher doses. CONCLUSION: Paroxetine appeared generally tolerated in short- and long-term use, and the safety profile in this study was consistent with international trials and other Japanese populations (i.e. patients suffering from depression, panic disorder or obsessive-compulsive disorder). Although the study was not conducted in double-blind fashion, the current findings suggest that paroxetine may contribute to clinically meaningful improvement that is maintained during long-term use and is generally well tolerated.