Sleep complaints are associated with reduced left prefrontal activation during a verbal fluency task in patients with major depression: A multi-channel near-infrared spectroscopy study.

BACKGROUND: Recent studies have indicated the potential clinical use of near-infrared spectroscopy (NIRS) as a tool for assisting in the diagnosis of major depressive disorder (MDD). Although sleep complaints are often manifested in MDD, no study has elucidated the possible association between the objective evaluation of sleep and NIRS signals in MDD. METHODS: Fourteen patients with MDD and 15 healthy controls wore waist actigraphy equipment before the NIRS scan to investigate sleep parameters. We performed a 52-channel NIRS scan and measured changes in oxygenated hemoglobin ([oxy-Hb]) during a verbal fluency task. RESULTS: In patients with MDD, a significant negative correlation was observed between the 17-item Hamilton Depressive Rating Scale score and cerebral reactivity of the right temporal region (ps:=-0.804 to -0.762; FDR-corrected; p=0.008-0.012). The Pittsburgh Sleep Questionnaire Index, which enables assessment of continuous sleep quality and disturbances, was negatively correlated with [oxy-Hb] changes in the left prefrontal cortex (ps=-0.630 to -0.551; FDR-corrected; p=0.043-0.048). Actigraphic sleep variables prior to the NIRS measurement showed no significant correlation with [oxy-Hb] changes. LIMITATIONS: The limitations were small sample size with the low severity of depression and the use of actigraphy for only one night. CONCLUSION: Self-rated sleep disturbance were associated with decreased left prefrontal reactivity during a verbal fluency task in patients with MDD. Our result indicates that the reactivity of the prefrontal region is susceptible to sleep complaints, providing further evidence to support potential clinical application of NIRS.

[Effects of psychological distress due to the Great East Japan Earthquake, tsunami, Fukushima Nuclear Power Plant disasters on psychiatric symptoms in patients with mental disorders: observational studies in Tochigi].

BACKGROUND: The Great East Japan Earthquake and subsequent tsunami of March 11, 2011 severely damaged a widespread region of northeastern Japan. Consequently, the Fukushima Nuclear Power Plant experienced a level seven 3 reactors melted down, which released a large amount of radioactive materials into the air. Due to the structural damage and radiation leaks, the victims are facing prolonged psychological distress. METHODS: Eighty-two subjects with mental disorders who made their initial visit during the first 4 months after the earthquake and one hundred and ninety-four subjects with mental disorders who had been admitted during the first one year after the earthquake to the Jichi Medical University Hospital, which is located at the edge of the disaster-stricken region, were recruited for this study. Enrolled participants were assessed according to ICD-10. A questionnaire survey was employed to evaluate the severity of psychological distress and total amount of damage. RESULTS: The conditions of 22% of the outpatients had been worsened by the psychological distress related to the earthquake. Seven percent of the patients who had been hospitalized showed marked exacerbations due to the psychological distress associated with the disaster. COMMENTS: It is of note that the exacerbation of psychiatric symptoms due to the disaster was evident among patients with mental disorders who lived even at the edge of the disaster area (i. e., subject to an earthquake intensity of 5 upper and 150 km from the Fukushima Nuclear Power Plant). The results suggest that the close follow-up of disaster victims with mental disorders is of critical importance.