Sleep-competing behaviours among Australian school-attending youth: Associations with sleep,mental health and daytime functioning

Sleep problems are highly prevalent among school-attending youth, and impact on school performance and outcomes. Sleep-competing behaviours are likely factors in the inadequate sleep time and related functional outcomes observed in this population. We examined a range of sleep-competing behaviours and their associations with sleep variables in Australian school-attending youth. We also assessed whether these behaviours indirectly affected mental health and daytime functioning through poorer sleep quality. A total of 353 school-attending youth (mean age = 14.6 years, 53% female) were recruited from high schools in Australia, and completed a range of self-report measures. Approximately 50% of the youth obtained sub-optimal levels of sleep and reported having a problematically long sleep onset latency. Sleep competing behaviours, related and unrelated to electronic media use, were reported as occurring frequently, and were associated with a range of sleep variables. These behaviours were also related to poorer mental health and daytime sleepiness, with this association explained by indirect effects through sleep quality. Sleep-competing behaviours are prevalent on school nights in Australian youth, and may have adverse associations with mental health and functioning. Prevention and intervention programs might address the risk factors identified in the current study.     

Examination of a multi-factorial model of body-related experiences during pregnancy: the relationships among physical symptoms, sleep quality, depression, self-esteem, and negative body attitudes

The aim of this cross-sectional study was to investigate relationships among women's body attitudes, physical symptoms, self-esteem, depression, and sleep quality during pregnancy. Pregnant women (N = 215) at 15–25 weeks gestation completed a questionnaire including four body image subscales assessing self-reported feeling fat, attractiveness, strength/fitness, and salience of weight and shape. Women reported on 29 pregnancy-related physical complaints, and completed the Beck Depression Inventory, Rosenberg Self-esteem Scale, and Pittsburgh Sleep Quality Index. In regressions, controlling for retrospective reports of body image, more frequent and intense physical symptoms were related to viewing the self as less strong/fit, and to poorer sleep quality and more depressive symptoms. In a multi-factorial model extending previous research, paths were found from sleep quality to depressive symptoms to self-esteem; self-esteem was found to be a mediator associated with lower scores on feeling fat and salience of weight and shape, and on higher perceived attractiveness.     

Effects of different substance misuse in genital reflexes of paradoxical sleep deprived male rats

As psychostimulants are widely abused, their neurochemical and behavioral effects have been extensively studied for many years. Our previous data demonstrate that paradoxical sleep deprivation (PSD) enhances drug-induced penile erection and ejaculation. PSD in association to drugs of abuse like cocaine potentiated genital reflexes in male rats. In this sense, the present study investigated if three substances abused by young people--such as Delta(9)-tetrahydrocannabinol (Delta(9)THC), alcohol and caffeine--had any significant effect on the genital reflexes in PSD rats. The results indicated that PSD induced erection in 50% of the rats and 20% ejaculated. In addition, there was no significant alteration in the number of animals exhibiting genital reflexes neither on the frequency of these behaviors when challenged with Delta(9)-THC or alcohol or caffeine after 96 h of PSD. These findings show that Delta(9)THC, alcohol and caffeine when administrated isolated did not produce alterations in genital reflexes in the PSD male rats.     

Intrinsic and extrinsic factors associated with night waking in 9-month-old infants

This study examined relations between infant night waking and both daytime behaviors reflective of poor behavioral and emotional regulation (intrinsic factors) and parent behaviors that may contribute to infant night waking (extrinsic factors) in 41 infants. Mothers completed questionnaires and an infant sleep and crying diary. More time awake at night was related to separation distress, frequent daytime crying, dysregulation, co-sleeping with parents, breast feeding, and being put to bed asleep. More frequent waking was related to separation distress, frequent daytime crying, co-sleeping, and breast feeding. The combination of intrinsic and extrinsic factors predicted night waking better than behaviors from one category alone. Implications for parenting are discussed.     

Sleep and psychopathology

This article examines the relationship between sleep disturbance and psychopathology. Epidemiological, cross-sectional, and longitudinal data suggest a high rate of comorbidity between sleep disturbance and psychopathology, particularly between insomnia, anxiety, and depression. Between 50% and 80% of psychiatric patients complain of sleep disturbances during the acute phase of their illness. Conversely, among treatment-seeking individuals with a primary complaint of insomnia and randomly selected community samples, approximately one third display a concurrent psychopathology, one third exhibit psychological symptoms that do not necessarily exceed the threshold for a psychiatric disorder, and another third present insomnia as a functionally autonomous disorder. There is a positive relationship between severity of sleep disturbances and concurrent psychopathology, but unequivocal evidence of a cause-and-effect relationship is still lacking. However, longitudinal data suggest that anxiety and stressful life events often precede acute sleep difficulties, whereas persistent insomnia may be a risk factor for subsequent development of depression. Implications for the prevention and treatment of coexisting sleep disturbance and psychopathology are discussed.     

Associations between mother-infant bed-sharing practices and infant affect and behavior during the still-face paradigm

Parents in the United States increasingly report bed-sharing with their infants (i.e., sleeping on a shared sleep surface), but the relationship between bed-sharing and child socioemotional outcomes are not well understood. The current study examines the links between mother-infant bed-sharing at 3 months and infant affect and behavior during a dyadic challenge task at 6 months. Further, we examine nighttime mother-infant contact at 3 months as a possible mechanism that may mediate linkages between bed-sharing and infant outcomes. Using observational data from a sample of 63 mother-infant dyads, we found that infants who bed-shared for any proportion of the observation period at 3 months displayed significantly more self-regulatory behaviors during the still-face episode of the Still-Face Paradigm (SFP) at 6 months, compared to non-bed-sharing infants. Also, infants of mothers who bed-shared for the entire observation period displayed significantly less negativity during the reunion episode than non-bed-sharing infants. There was no evidence that the relations between mother-infant bed-sharing practices and infant affect and behavior during the SFP were mediated through nighttime mother-infant contact. Results suggest that infant regulation at 6 months postpartum may vary based on early nighttime experiences, with bed-sharing potentially promoting more positive and well-regulated behavior during dyadic interaction.     

Dream engineering: Simulating worlds through sensory stimulation

We explore the application of a wide range of sensory stimulation technologies to the area of sleep and dream engineering. We begin by emphasizing the causal role of the body in dream generation, and describe a circuitry between the sleeping body and the dreaming mind. We suggest that nearly any sensory stimuli has potential for modulating experience in sleep. Considering other areas that might afford tools for engineering sensory content in simulated worlds, we turn to Virtual Reality (VR). We outline a collection of relevant VR technologies, including devices engineered to stimulate haptic, temperature, vestibular, olfactory, and auditory sensations. We believe these technologies, which have been developed for high mobility and low cost, can be translated to the field of dream engineering. We close by discussing possible future directions in this field and the ethics of a world in which targeted dream direction and sleep manipulation are feasible.