Kiyohisa Takahashi

Morning bright light therapy for sleep and behavior disorders in elderly patients with dementia

Fourteen inpatients with dementia showing sleep and behavior disorders (average age = 75 years), and 10 control elderly people (average age = 75 years) were carefully observed for 2 months. Four weeks of morning light therapy markedly improved sleep and behavior disorders in the dementia group. The measurement of sleep time and the serum melatonin values suggests that sleep and behavior disorders in the dementia group are related to decreases in the amplitude of the sleep‐wake rhythm and decreases in the levels of melatonin secretions. Morning light therapy significantly increased total and nocturnal sleep time and significantly decreased daytime sleep time. These results indicate that morning bright light is a powerful synchronizer that can normalize disturbed sleep and substantially reduce the frequency of behavior disorders in elderly people with dementia.

Time to recurrence after recovery from major depressive episodes and its predictors.

BACKGROUND Depression is a remitting but recurring disease. However, there is a paucity of prospectively recorded data on the course of depression after recovery. METHOD A multi-centre prospective serial follow-up study of an inception cohort of hitherto untreated unipolar major depression (N = 95) for 6 years. We report the time to recurrence after recovery from the index depressive episode and their predictors. RESULTS The cumulative probability of remaining well without subthreshold symptoms was 57% (95% CI, 46 to 68%) at 1 year, 47% (95% CI, 36 to 58%) at 2 years and 35% (95% CI, 23 to 47%) at 5 years. The same without full relapse was 79% (95% CI, 70 to 88%) at 1 year, 70% (95% CI, 60 to 80%) at 2 years and 58% (95% CI, 46 to 70%) at 5 years. The median duration of well-interval from the end of the index episode to the beginning of the subthreshold episode was 19-0 months (95% CI, 2-4 to 35-7), and that to the end of the full episode was over 6 years. Residual symptoms at time of recovery predicted earlier recurrence. CONCLUSIONS The median length of the well-interval was much longer than previously reported in studies employing similar definitions but dealing with a more severe spectrum of patients. However, the sobering fact remains that less than half of the patients can expect to remain virtually symptom-free for 2 years or more after recovery from the depressive episode.

Social support questionnaire among psychiatric patients with various diagnoses and normal controls

AbstractBackground: Several studies have pointed to the importance of social support in influencing the onset and course of a psychiatric disorder such as schizophrenia or depression. However, only a few have studied it across groups of patients with various psychiatric diagnoses employing a standardized assessment procedure. Method: We administered the Social Support Questionnaire (SSQ); a measure of social support recommended by two recent reviews on the subject, to 1,369 psychiatric outpatients visiting the 23 psychiatric hospitals and clinics all over Japan and to 178 healthy controls recruited from among employees at a general hospital. Results: The original two-factor structure of the SSQ was confirmed and internal consistency reliability for the Number and Satisfaction subscales was satisfactory, with Cronbachs alphas above 0.85. When the SSQ scores were compared between psychiatric patients and healthy controls, it was found that the psychiatric patients in general reported significantly lower Number as well as Satisfaction scores than the healthy controls. When individual diagnostic categories were considered, almost all the diagnostic groups reported significantly lower Number scores, but only the patients with anxiety disorder, mood disorder, schizophrenia, and V codes reported significantly lower Satisfaction scores than the healthy controls. Compared with patients with other diagnoses, the schizophrenic patients stood out as reporting significantly lower Number and Satisfaction scores. Conclusion: The findings demonstrated the internal consistency reliability, factor validity, and construct validity of the SSQ among psychiatric as well as normal populations, and exemplified the feasibility of applying the SSQ as a standard measure of social support among psychiatric patients.

Seasonal variation of mood and behaviour in a healthy middle‐aged population in Japan

A population survey of seasonality in six representative cities in Japan was conducted using the Japanese version of the Seasonal Pattern Assessment Questionnaire (SPAQ). The questionnaires were given to 951 parents (male: female ratio 1 : 1 age range 34‐59 years) of high‐school students. Significant regional differences in seasonal variations of mood, length of sleep, and weight were observed; the proportion of individuals reporting high seasonality in the two northern cities was significantly higher than that in the other areas. These results provide evidence for a northern predominance in the prevalence of seasonal affective disorder in Japan.

Early parental separation experiences among patients with bipolar disorder and major depression: a case–control study

BACKGROUND Although the association between childhood parental loss and later development of mood disorder has received much research interest in the past, the results obtained and conclusions drawn have been various, and inconsistent with each other. The present study aims to examine this old, yet unresolved, question among the Japanese. METHODS Patients with bipolar disorder (n = 73) and unipolar depression (n = 570) and community healthy controls (n = 122) were examined as to their psychopathology and childhood parental loss experiences with semi-structured interviews. RESULTS Stratified for sex and age, no statistically significant difference was observed in the incidence of paternal or maternal death or separation before age 16 between bipolar patients and healthy controls. Female patients with unipolar depression under the age of 54 experienced significantly more maternal loss than the corresponding controls. This excess in loss appeared to be largely due to the patients experiencing separation from their mothers. CONCLUSION Our findings concerning bipolar disorder have replicated the previous two studies reported in the literature. Those concerning unipolar depression appear to be in line with several recent studies on the subject but, as stated, many discrepant findings can also be found in the literature.

Relationship between free-running period and motor activity in blinded rats

The free-running rhythms of motor activity in blinded rats were measured by two different devices, an Automex or a running wheel. The period of free-running rhythm measured by a running wheel was likely to be shorter than that measured by an Automex, indicating that subtle environmental difference, such as whether a cage is equipped with a wheel or not, can affect the free-running period. In addition, we found a negative correlation not only between the free-running period measured by a running wheel and that measured by an Automex, but between the free-running period and the number of wheel revolutions per day. This is the first evidence that motor activity, other than the external factors such as light intensity and temperature, may be related to change in the free-running period.

Effect of light on the acetylcholine concentrations of the suprachiasmatic nucleus in the rat.

Acetylcholine concentrations were determined in suprachiasmatic nucleus of rats sacrificed by irradiation of microwave, using radioimmunoassay. No significant rhythmicity was observed over a 24-h period in rats blinded for two weeks. When the light was given at 22.00 h (illumination schedule L:07.00-19.00 h) in intact rats, acetylcholine concentration increased 30 and 60 min after light on in suprachiasmatic nucleus, but not in the other control site. These results suggest that endogenous circadian rhythm of acetylcholine concentration is absent in suprachiasmatic nucleus, but light may affect acetylcholine concentration of this site.

Entrainment of the circadian rhythms of blinded infant rats by nursing mothers

New-born rats were optically enucleated on day 1 and the rhythms of pineal serotonin N-acetyltransferase activity and serum corticosterone levels were followed under various nursing schedules from 4 to 8 weeks of ages. When blinded pups born under DL (LD) cycle were reared by foster mothers under LD (DL) cycle, both of N-acetyltransferase and corticosterone rhythms were in phase with those of the pups born of and reared by their original mothers under LD (DL) cycle. The phases of the rhythms were regularly delayed at a similar rate in 4 groups as they grew, indicating that nursing mother rats can entrain the circadian rhythms of blinded pups. When intact and blinded pups were reared under LD cycle, the phases of N-acetyltransferase activity rhythm in both groups were identical at the first postnatal week, but the phase of the rhythm in blinded pups was gradually delayed after second week compared to intact pups. The observation indicates that the endogenous oscillation in blinded pups starts to free-run between 1 and 2 weeks after birth.

Emerging and entraining patterns of the sleep–wake rhythm in preterm and term infants

It has been repeatedly reported that the sleep-wake rhythm in infants entrains around 3-4 months of age after a transient free-run rhythm. To clarify the emerging and entraining patterns of the sleep-wake rhythm, the sleep and wakefulness of 84 infants (44 preterm and 40 term infants) were longitudinally recorded at home for more than 16 weeks by the day-by-day plot method. Our results showed that the entrained sleep-wake rhythm emerged after transient manifestation of either ultradian or irregular sleep-wake patterns for 3-4 weeks in 75% of the infants. Only 7% of the infants showed a free-running sleep-wake rhythm before the entrainment. These facts suggest that most infants would be entrained to an ordinary daily schedule of mothers without expression of overt free-running rhythm of the biological clock. The mean age of the entrainment was 44.8 postconceptional weeks. There were no significant differences in either frequency of each pattern or the mean age of the entrainment, between preterm and term infants. In conclusion, the entrained sleep-wake rhythm emerges around 1 corrected month, after ultradian patterns in the majority of infants.

Change in period of free-running rhythms determined by two different tools in blinded rats.

Drinking rhythm in 6 rats optically enucleated on the day of birth was determined every one to two weeks after weaning until the age of 28 weeks. Each rat was transferred repeatedly from a cage without a running wheel to one with a running wheel, and vice versa. During the periods when the rats were housed in the former cage, drinking rhythm delayed, while it advanced when they were housed in the latter. The rats, which had a period of free-running rhythm of motor activity longer than 24 hr when measured by an Automex device in a cage without a running wheel, showed a period shorter than 24 hr when measured by a running wheel. These results suggest that the difference in tools for determination of activity may influence the results of animal experiments for free-running rhythm, and warn investigators of risks being caused by the selection of tools.