Faculty Bibliography

Researchers have found that melatonin substantially reduced both sleep onset latency and the number of nocturnal awakenings in normal individuals as well as patients with diverse sleep pathologies. These findings have led to an increase in the number of individuals who ingest melatonin habitually to alleviate their sleep problem. Given the widespread use of melatonin, it is important to identify the factors capable of predicting physiological states while following a melatonin regimen. The result of this preliminary analysis showed that the number of hours spent outdoors is the best predictor of subjective sleepiness while under the influence of melatonin. Specifically, the more time individuals spend outdoors, the sleepier they are when administered melatonin.

Research evidence suggests that actigraphy is a very important instrument in documenting sleep/wake patterns of people with a variety of sleep disorders or motor dysfunctions. The present actigraphic investigation examined physical activity and sleep profiles as a function of gender in volunteers monitored in their natural environment. Irrespective of age, women exhibited better sleep quality than did men. This was demonstrated by higher sleep efficiency index and lower frequency of transitions between sleep and wakefulness. Additionally, women slept more than men and had shorter sleep onset latency. However, no significant gender effect on daytime activity level and circadian activity amplitude was observed.

OBJECTIVE: Depressed mood is one of the essential features for the diagnosis of major depression. Evidence from the three-site Epidemiologic Catchment Area study (ECA, Baltimore, Durham and Los Angeles) suggests a prevalence of 4.4% of depressive symptoms in the community. In this study, we examined whether depressed mood, as coded in the Alzheimer's Disease Assessment Scale, would be correlated with actigraphic-derived daytime activity and sleep/wake parameters in a non-psychiatric sample. METHOD: Consenting volunteers were monitored at home for 5 days with a wrist actigraph. On the last day of the recording, they were given a neuropsychological battery including the Alzheimer's Disease Assessment Scale. RESULTS: Daytime activity level was the best predictor of depressed mood as indicated by a logistic regression analysis. The regression model further suggested that sleep onset latency, total time asleep, and time in bed were also significant predictors of depressed mood. CONCLUSION: This investigation demonstrates that daytime activity level could be used as an index of depressed mood even in a non-psychiatric sample. Further, the results support the notion that depression should be considered more as a continuum rather than as a set of rigid categories.

This is a retrospective study of mothers charged with killing their children within 24 h of birth in the city of Rio de Janeiro, Brazil. Characteristics of the mothers and the victims, the circumstances surrounding the offense, the mothers' motivation and state of mind at the time of the offense, the legal process, and follow-up data were investigated. We analyzed our cohort as two sub-groups: 26 offenses that occurred between 1900 and 1939 and were dealt with under the Brazilian Penal Code of 1890, and 27 offenses that were committed between 1940 and 1995 and were dealt with under the Penal Code of 1940. The mothers were young (mean 22.5 +/- 5.3 years), unmarried (88.2%), non-Caucasian (73.8%), and had limited formal education. They usually kept the pregnancy a secret (94.1%) and gave birth in a classified way (100%). Most victims were killed through wounding violence (77.4%). Offenders identified between the years of 1940-1995 had increased rates of literacy (chi 2 = 6.80, d.f. = 1, p = .009), a higher incidence of reported psychiatric symptoms (chi 2 = 11.82, d.f. = 1, p < .001), increased referral for psychiatric assessment (chi 2 = 3.85, d.f. = 1, p = .05), and greater frequency of cases where statute of limitations was expired (chi 2 = 3.88, d.f. = 1, p = .049).

The usefulness of the actigraph methodology has been demonstrated in normal individuals. However, the validity of actigraphy has been questioned in insomnia patients because of the considerable measurement error that has been reported between actigraphy (ACT) and polysomnography (PSG). Two independent investigations have reported errors of 48 and 49 min in total sleep time between ACT and PSG. With a new scoring method called the Actigraph Data Analysis Software, a reanalysis of one of these studies was conducted. Based on this reanalysis, we have obtained a measurement error of only 25 min between the two methods. This finding may be an indication of the advantage of this new scoring method. A strong correlation coefficient (r = 0.82, p < 0.0001) was noted between ACT and PSG for total sleep time, thus suggesting a high degree of accuracy of the actigraph methodology in assessing the sleep/wake profile of insomniacs.

Survey and laboratory evidence suggests several factors affecting sleep-wake patterns of college students. These factors include social and academic demands, diminution of parental guidance, reduction of total sleep time, delayed bedtime, and increased nap episodes. In this study, we examined the problem of falling asleep in school as a correlate of negative moods in this population (N = 294). A multivariate analysis showed significant main effects of sleepiness on mood states based on the Profile of Mood States. Students who fell asleep in school reported higher negative mood states. Significant interactions were observed among sleepiness and age, sex, race, and duration of sleep. Specifically, younger men reported higher negative moods. No interactions were noted for alcohol and marijuana consumption; however, students who fell asleep in school consumed more alcoholic beverages and smoked more than those who did not. Perhaps falling asleep in school could be used as an index that characterizes students who manifest adaptive or psychological difficulty.

Dementia has been associated with circadian rhythm disturbances expressed in several dimensions including body temperature, hormonal concentrations, sleep and wakefulness patterns, and rest-activity cycles. These disturbances may be the result of a dampening in the amplitude of the circadian rhythm. One of the symptoms associated with the aging process has been a decline in the amplitude of the melatonin rhythm. Here, the results of melatonin administration to two patients with Alzheimer's disease are presented. Melatonin administration enhanced and stabilized the circadian rest-activity rhythm in one of the patients along with some reduction of daytime sleepiness and an improvement in mood. The other patient, who was characterized by less cognitive impairment, showed no significant changes associated with melatonin ingestion. Interestingly, the acrophase of rest-activity was delayed for about one hour in both patients. These results suggest that melatonin may have beneficial effects in some patients with Alzheimer's disease.

The effects of immediate-release melatonin on circadian rest-activity profiles, cognition, and mood were investigated in ten elderly individuals with self-reported sleep-wake disturbances. Melatonin (6 mg), administered 2 hr before habitual bedtime, enhanced the rest-activity rhythm and improved sleep quality as observed in a reduction in sleep onset latency and in the number of transitions from sleep to wakefulness. However, total sleep time was not significantly increased nor was wake within sleep significantly reduced. The ability to remember previously learned items improved along with a significant reduction in depressed moods. No side effects or contraindications were reported by any of our participants during the 10 day trials. These data suggest that melatonin can safely improve some aspects of sleep, memory, and mood in the elderly in short-term use.

The EEG photic driving response is a sensitive neurophysiological measure. It has been used to assess drug effects, forms of epilepsy, neurological status of Alzheimer's patients, and physiological arousal. Photic driving also impacts the psychological status of a person by producing increased visual imagery and decreased physiological and subjective arousal. In this study, ten volunteers underwent nocturnal polysomnography followed by six daytime testing sessions. The six sessions consisted of the alpha attenuation test, two visual analog scales for mood, the Stanford Sleepiness Scale, photic stimulation, and the multiple sleep latency test. These tests were administered 2 hours upon awakening and every 2 hours thereafter. The mean mood across the six daytime testing sessions was computed for all mood variables pre- and post-photic stimulation. Significant differences were found for the subjective moods "sleepy," "alert," and "effort." However, no significant differences were found for pre- and post-photic driving for "angry," "irritable," "hungry," "tense," "overall," "happy," "sexual," and "sad." Additionally, all participants reported increased visual imagery during photic driving, as measured by their responses to an imagery questionnaire.