Alterations of neural network organization during REM sleep in women: implication for sex differences in vulnerability to mood disorders

Sex Differences in Sleep Architecture After Traumatic Brain Injury: Potential Implications on Short-Term Episodic Memory and Recovery

Sleep-wake disturbances (SWDs) are common after TBI and often extend into the chronic phase of recovery. Such disturbances in sleep can lead to deficits in executive functioning, attention, and memory consolidation, which may ultimately impact the recovery process. We examined whether SWDs post-TBI were associated with morbidity during the post-acute period. Particular attention was placed on the impact of sleep architecture on learning and memory. Because women are more likely to report SWDs, we examined sex as a biological variable. We also examined subjective quality of life, depression, and disability levels. Data were retrospectively analyzed for 57 TBI patients who underwent an overnight polysomnography. Medical records were reviewed to determine cognitive and functional status during the period of the sleep evaluation. Consideration was given to medications, owing to the fact that a high number of these are likely to have secondary influences on sleep characteristics. Women showed higher levels of disability and reported more depression and lower quality of life. A sex-dependent disruption in sleep architecture was observed, with women having lower percent time in REM sleep. An association between percent time in REM and better episodic memory scores was found. Melatonin utilization had a positive impact on REM duration. Improvements in understanding the impact of sleep-wake disturbances on post-TBI outcome will aid in defining targeted interventions for this population. Findings from this study support the hypothesis that decreases in REM sleep may contribute to chronic disability and underlie the importance of considering sex differences when addressing sleep.

Women's mood at high altitude. sexual dimorphism in hypoxic stress modulation by the tryptophan-melatonin axis

Sexual (and gender)-dimorphism in tolerance to hypobaric hypoxia increasingly matters for a differential surveillance of human activities at high altitude (HA). At low altitudes, the prevalence of anxiety and depression in women has already been found to double when compared with men; it could be expected to even increase on exposure to HA. In purposefully caring for the health of women at HA, the present work explores the potential involvement of the tryptophan (Trp)-melatonin axis in mood changes on exposure to hypobaric hypoxia. The present work highlights some already known anxiogenic effects of HA exposure. Hypoxia and insomnia reduce serotonin (5-HT) availability; the latter defect being expressed as failure of brown adipose tissue (BAT) activation and mood disorders. Rapid eye movement (REM) sleep organization and synapsis restoration that are additionally affected by hypoxia impair memory consolidation. Affective complaints may thus surge, evolving into anxiety and depression. Sex-related differences in neural network organization and hormonal changes during the menstrual cycle, and certainly also during the life cycle, underscore the possibility of 5-HT-related mood alterations, particularly in women on HA exposure. The mean brain rate of 5-HT synthesis at sea level is already 1.5-fold higher in males than in females. sexual dimorphism also evidences the overexpression effects of SERT, a 5-HT transporter protein. Gonadal and thyroid hormones, as influenced by HA exposure, further modulate 5-HT availability and its effects in women. Besides caring for adequate oxygenation and maintenance of one's body core temperature, special precautions concerning women sojourning at HA should include close observations of hormonal cycles and, perhaps, also trials with targeted antidepressants.

Out-of-home placement, sleep problems, and later mental health and crime: A prospective investigation

Previous research suggests that out-of-home placement experiences increase the risk for mental health problems and criminal involvement. However, few studies have examined the mechanisms whereby out-of-home placement increases the risk for these outcomes. The present study examines whether sleep problems in part explain the relationship between childhood placement experiences and depression and anxiety and criminal arrests in adulthood. Data are from a prospective longitudinal study of 531 children with documented cases of childhood maltreatment (14% with no out-of-home placement, 68% placed solely for abuse and/or neglect, and 18% placed for maltreatment and delinquency) who were followed up into adulthood. Cases are from 1967 to 1971 from a metropolitan county in the Midwest. Sleep problems were assessed in young adulthood (M_age = 29 years). Depression and anxiety symptoms and arrest records were assessed in middle adulthood (M_age = 40 years). Structural equation modeling was used to test hypotheses. Both types of out-of-home placement experiences (for maltreatment only and for maltreatment and delinquency) predicted more sleep problems in adulthood across all models. Sleep problems in young adulthood predicted higher levels of anxiety and depression in middle adulthood, but not criminal arrests. Sleep problems mediated the relationship between placement only and internalizing symptoms and results differed for male, female, White, and Black individuals examined separately. Using court-substantiated cases of childhood abuse and neglect, this study demonstrates the long-term negative consequences of out-of-home placement experiences for sleep problems and anxiety and depression in adulthood. More attention is needed to insure adequate sleep for maltreated children. (PsycInfo Database Record (c) 2022 APA, all rights reserved).