Role of school schedule, age, and parental socioeconomic status on sleep duration and sleepiness of Parisian children.

The aim of the study was to assess the duration and quality of sleep of prepubertal (Tanner Scale level 1) physically and mentally healthy children as a function of school schedule (4 versus 4.5 days per week), age and grade (median age of 9.5 years for 4th grade versus median age of 10.5 years for 5th grade), school district (wealthy versus nonwealthy) in Paris, France, and parental socioeconomic status (high, medium, or low). We studied 51 girl and 44 boy volunteer pupils with written parental consent. The study lasted 2 weeks during the month of March. During the first study week, the children attended school 4.5 days, and during the second week, they attended school only 4 days without difference in the length of the school day. A sleep log was used to ascertain time of lights off for sleep and lights on at awakening, nighttime sleep duration, and self-rated sleep quality. A visual analog scale (VAS) was also used by pupils to self-rate the level of perceived sleepiness at four specific times of the school day. Conventional statistical methods (e.g., t and chi2 tests) were used to examine differences in mean values. Sleep duration, self-rated sleepiness, and subjective sleep quality were comparable (P > .05) by gender, school schedule, school district, and parental socioeconomic status. Overall, the sleep of this sample of Parisian children around 10 years of age was rather stable in its duration and timing, suggesting flexibility to adjust to the different school schedules.

Alcohol dependence among patients admitted to psychiatric emergency services.

We assessed the prevalence of alcohol dependence among patients examined in the psychiatric emergency service of a general hospital. We compared socio-demographic data and psychiatric status of patients with and without alcohol dependence. One-hundred and four consecutive patients received by the psychiatric emergency service of Bichat-Claude Bernard Hospital (Paris, France) were assessed. Diagnosis of alcohol dependence, acute alcohol intoxication, and antisocial personality was determined according to DSM-IV criteria. Other psychiatric disorders were identified using a structured psychiatric interview, the Mini International Neuropsychiatric Interview (MINI). Prevalency rate of alcohol dependence was 37.5% among patients examined by the psychiatric emergency service. Alcohol-dependent patients were more often men than women and more often unemployed than non-alcohol-dependent psychiatric emergencies. They presented more dysthymia, acute alcohol intoxication, and antisocial personality than non-alcoholic patients followed by the psychiatric emergency service. Attempted suicide was as frequent in alcohol-dependent patients (23%) as in other patients (29%). Alcohol-dependent patients consumed alcohol more often when alone, and their alcohol consumption began more frequently in the morning. Patients seen in a psychiatric emergency service must be identified as a population at risk for alcohol dependence (37.5%). Alcohol-dependent patients are more often men and have a higher rate of unemployment. They present significantly more often dysthymia and acute alcohol intoxication associated to alcohol dependence.

Weekly changes in psychophysiological variables of 8- to 10-year-old school girls.

Three groups of schoolgirls 8, 9, and 10 years of age, respectively, self assessed sleep onset/offset and duration, as well as oral temperature and a set of cognitive measures, at school at 09:00, 11:00, 14:00, and 16:00 h on Mondays, Tuesdays, Thursdays, and Fridays (and/or Saturday) for 2 consecutive weeks (spring 1987 and 1989). The scores of a letter cancellation test exhibited neither daily nor weekly temporal variation at the age of 8 years [analysis of variance (ANOVA), p > 0.05]. In contrast, in the 10-year-olds, changes as a function of both time of day (peak time 14:00-16:00 h) and day of week (peak day Tuesday-Friday) were substantiated. Moreover, the time of best performance on the letter cancellation test varied systematically according to the day of the week (ANOVA, p = 0.000). Day of the week changes in the observed duration of sleep, self-rated fatigue, drowsiness, and attention changes were not detected in any of the age groups. It is hypothesized that temporal performance variations in the girls during the 7-day period was age related.

Diurnal changes in psychophysiological variables of school girls: comparison with regard to age and teacher's appreciation of learning.

Ninety-five nonresident girls of a private school volunteered for the study with the teachers' help as well as parental consent. Ages were approximately 8, 9, and 10 years. They were synchronized with diurnal activity from 0730 to 2100 h and nocturnal rest. Fatigue, drowsiness, and attention were self-rated using visual analogue scales; oral temperature was self-measured and a letter cancellation test was performed. Each of these variables was measured at school at 0900, 1100, 1400, and 1600 h on Mondays, Thursdays, Fridays, and Saturdays for two consecutive weeks in 1987 (March 30-April 11) and again in 1989 (March 13-25) when the youngest group had become 10 years old. According to conventional teacher evaluation of learning (learning performance) within each group, three subgroups were formed: top third, middle third, and bottom third. Time series (more than 50,000 data) were analyzed according to several statistical methods, but mainly chronograms with ANOVA. Similar diurnal changes in oral temperature were validated for each group and subgroups. The occurrence of a diurnal change in self-rated variables (fatigue and drowsiness) and score in letter cancellation was age related: no detection in the 8-year-old group (and subgroups) and validation (p less than 0.002) in 9- and 10-year-old groups (and respective subgroups). A good learning performance was associated with a reduced drowsiness in school girls of 9 and 10 years. Age-related, time-of-day differences in drowsiness (when detected) as well as learning performance effect were not associated with observed duration of sleep. Validated changes in self-rated fatigue were close to that of drowsiness. At 0900 h, girls of 9 and 10 years were more tired when belonging to the bottom third than top third subgroup. Whatever the time of day, self-rated attention was greater in the top than in the bottom third for these girls. Differences related to learning performance were validated in each grade. However, best scores were recorded for the bottom third in the 8-year-old group, while best scores were provided by top third subgroups in 10-year-old girls. It seems that in girls around 8 years of age, critical changes can be detected with regard to the (ontogenic?) occurrence of time-of-day differences in a set of psychophysiologic variables as well as influential effects of learning performance on the same variables. Reported finding are compatible with the hypothesis of circadian oscillators working at the level of the cortex of the human brain.