Daily affective experiences predict objective sleep outcomes among adolescents.

Adolescence is a sensitive period for changes in both sleep and affect. Although past research has assessed the association between affect and sleep among adolescents, few studies have examined both trait (typical) and day-to-day changes in affect, and fewer still have specifically examined negative social evaluative emotions (e.g. embarrassment) in relation to sleep. Both between- and within-person variations in daily affect were examined in relation to four objectively-measured sleep outcomes (sleep hours; sleep latency; sleep efficiency; and length of wake bouts) among adolescents. Participants (N = 77 high-school students; 42.9% female; M = 14.37 years) wore an actiwatch and completed daily-diaries for 3 days. The results of hierarchical linear models (controlling for age, gender, race, ethnicity, parental employment status, income, puberty and caffeine) indicated that negative social evaluative emotions and high-arousal affective experiences generally predicted poor sleep outcomes, whereas low-arousal affective experiences were associated with good sleep outcomes. Specifically, at the person level, adolescents reporting higher negative social evaluative emotions had shorter average sleep hours, and those experiencing higher anxiety­nervousness had longer wake bouts. In addition, individuals experiencing more dysphoria (sad, depressed, lonely) had longer average sleep hours and shorter wake bouts, while those experiencing more calmness had shorter sleep latencies. At the within-person level, individuals had longer sleep latencies following days that they had experienced high-arousal positive affect (e.g. excitement), and had longer wake bouts following days they had experienced more negative social evaluative emotions. The results highlight the detrimental effects of negative social evaluative emotions and high-arousal affective states for adolescent sleep.

A longitudinal examination of the bidirectional association between sleep problems and social ties at university: the mediating role of emotion regulation.

Despite the growing body of research linking sleep problems and social ties, research investigating the direction of effects between these two constructs is lacking. Furthermore, there remains a dearth of research examining the mechanisms that may explain the association between sleep problems and social ties within a longitudinal design. The present 3-year longitudinal study addressed two research questions: (1) Is there a bidirectional association between sleep problems and social ties at university? and (2) Does emotion regulation mediate the association between sleep problems and social ties at university? Participants (N = 942, 71.5% female; M = 19.01 years at Time 1, SD = 0.90) were university students who completed annual assessments of sleep problems, social ties, and emotion regulation, for three consecutive years. Results of path analysis indicated that the bidirectional association between sleep problems and social ties was statistically significant (controlling for demographics, sleep-wake inconsistency, sleep duration, and alcohol). Analyses of indirect effects indicated that emotion regulation mediated this link, such that better sleep quality (i.e., less sleep problems) led to more effective emotion regulation, which, subsequently, led to more positive social ties. In addition, more positive social ties led to more effective emotion regulation, which, in turn, led to less sleep problems. The findings highlight the critical role that emotional regulation plays in the link between sleep problems and social ties, and emphasize the need for students as well as university administration to pay close attention to both the sleep and social environment of university students.

Sleep problems: predictor or outcome of media use among emerging adults at university?

The pervasiveness of media use in our society has raised concerns about its potential impact on important lifestyle behaviours, including sleep. Although a number of studies have modelled poor sleep as a negative outcome of media use, a critical assessment of the literature indicates two important gaps: (i) studies have almost exclusively relied on concurrent data, and thus have not been able to assess the direction of effects; and (ii) studies have largely been conducted with children and adolescents. The purpose of the present 3-year longitudinal study, therefore, was to examine whether both sleep duration and sleep problems would be predictors or outcomes of two forms of media use (i.e. television and online social networking) among a sample of emerging adults. Participants were 942 (71.5% female) university students (M = 19.01 years, SD = 0.90) at Time 1. Survey measures, which were assessed for three consecutive years starting in the first year of university, included demographics, sleep duration, sleep problems, television and online social networking use. Results of a cross-lagged model indicated that the association between sleep problems and media use was statistically significant: sleep problems predicted longer time spent watching television and on social networking websites, but not vice versa. Contrary to our hypotheses, sleep duration was not associated with media use. Our findings indicate no negative effects of media use on sleep among emerging adults, but instead suggest that emerging adults appear to seek out media as a means of coping with their sleep problems.

The triadic systems model perspective and adolescent risk taking.

In this special issue, Ernst (2014) outlines the triadic systems model, which focuses on the balanced interaction among three functional neural systems: the prefrontal cortex (regulation/control), striatum (motivation/approach), and amygdala (emotion/avoidance). Asynchrony in maturation timelines, coupled with less mature connectivity across brain regions, is thought to result in unique vulnerabilities for risk taking during the adolescent age period. Yet, the research evidence linking the triadic systems model to differences in risk taking across adolescence and adulthood is equivocal, and few studies have examined how neural development is associated with real-world behavior. In this commentary, we outline research on adolescent risk taking which highlights the importance of considering trait level and situational conditions when examining associations between neural systems and behavior, as well as the need to adopt a lifespan perspective.

Examining the link between adolescent brain development and risk taking from a social-developmental perspective (reprinted).

The adolescent age period is often characterized as a health paradox because it is a time of extensive increases in physical and mental capabilities, yet overall mortality/morbidity rates increase significantly from childhood to adolescence, often due to preventable causes such as risk taking. Asynchrony in developmental time courses between the affective/approach and cognitive control brain systems, as well as the ongoing maturation of neural connectivity are thought to lead to increased vulnerability for risk taking in adolescence. A critical analysis of the frequency of risk taking behaviors, as well as mortality and morbidity rates across the lifespan, however, challenges the hypothesis that the peak of risk taking occurs in middle adolescence when the asynchrony between the different developmental time courses of the affective/approach and cognitive control systems is the largest. In fact, the highest levels of risk taking behaviors, such as alcohol and drug use, often occur among emerging adults (e.g., university/college students), and highlight the role of the social context in predicting risk taking behavior. Moreover, risk taking is not always unregulated or impulsive. Future research should broaden the scope of risk taking to include risks that are relevant to older adults, such as risky financial investing, gambling, and marital infidelity. In addition, a lifespan perspective, with a focus on how associations between neural systems and behavior are moderated by context and trait-level characteristics, and which includes diverse samples (e.g., divorced individuals), will help to address some important limitations in the adolescent brain development and risk taking literature.

Examining the link between adolescent brain development and risk taking from a social-developmental perspective.

The adolescent age period is often characterized as a health paradox because it is a time of extensive increases in physical and mental capabilities, yet overall mortality/morbidity rates increase significantly from childhood to adolescence, often due to preventable causes such as risk taking. Asynchrony in developmental time courses between the affective/approach and cognitive control brain systems, as well as the ongoing maturation of neural connectivity are thought to lead to increased vulnerability for risk taking in adolescence. A critical analysis of the frequency of risk taking behaviors, as well as mortality and morbidity rates across the lifespan, however, challenges the hypothesis that the peak of risk taking occurs in middle adolescence when the asynchrony between the different developmental time courses of the affective/approach and cognitive control systems is the largest. In fact, the highest levels of risk taking behaviors, such as alcohol and drug use, often occur among emerging adults (e.g., university/college students), and highlight the role of the social context in predicting risk taking behavior. Moreover, risk taking is not always unregulated or impulsive. Future research should broaden the scope of risk taking to include risks that are relevant to older adults, such as risky financial investing, gambling, and marital infidelity. In addition, a lifespan perspective, with a focus on how associations between neural systems and behavior are moderated by context and trait-level characteristics, and which includes diverse samples (e.g., divorced individuals), will help to address some important limitations in the adolescent brain development and risk taking literature.

Be well, sleep well: An examination of directionality between basic psychological needs and subjective sleep among emerging adults at university.

OBJECTIVES: The present study assessed bidirectional associations between basic psychological needs and several subjective sleep variables across 2 semesters. DESIGN: Participants completed an online survey twice (7 months apart) as part of a short-term longitudinal, correlational study. PARTICIPANTS: Participants were 154 (67.8% female) emerging adults (mean age = 20.02 years, SD = 1.71) from a liberal arts university on the east coast. MEASUREMENTS: Survey assessed demographics, perceived fulfillment of basic psychological needs (autonomy, competence, and relatedness), and several sleep variables (week and weekend sleep duration, sleep disturbances, daytime dysfunction, and sleep quality; Pittsburgh Sleep Quality Index). RESULTS: Data were analyzed using an autoregressive cross-lagged model, which controlled for level of study, diagnosis of mental illness, self-esteem, social desirability, sleeping medication, chronotype, conscientiousness, and extraversion. Results indicated significant unidirectional associations: perceived fulfillment of basic psychological needs predicted longer week sleep duration (ß = .243, P = .008) and better perceived sleep quality (ß = -.223, P = .008) 1 semester later, and 1 significant bidirectional association, perceived fulfillment of basic psychological needs, predicted lower daytime dysfunction, and in turn, lower daytime dysfunction predicted higher perceived fulfillment of basic psychological needs 1 semester later. CONCLUSIONS: Although many sleep interventions focus on environmental aspects of sleep, our findings highlight the importance of nurturing university students' psychological needs as a potential point of intervention for improving some sleep characteristics among emerging adults at university.

Text message intervention improves objective sleep hours among adolescents: the moderating role of race-ethnicity.

OBJECTIVES: This 10-day study aimed to (1) assess the effectiveness of a text message-based sleep intervention and (2) determine whether the intervention was equally effective for non-Hispanic whites and racial-ethnic minority adolescents. PARTICIPANTS: Participants were 46 (50% female) adolescents (13-18 years; mean=15.75 years old, SD=0.98) from a public high school in the Midwest. INTERVENTION: Participants were randomly assigned to a control or text message intervention condition. Only participants in the intervention condition received 2 text messages outlining individualized bedtime goals daily, for 8 weekdays. MEASUREMENTS: All participants attended a sleep lecture, wore a sleep monitor, and completed baseline and exit surveys that assessed demographics, subjective sleep, lifestyle, and psychosocial adjustment variables. RESULTS: Results of a 2 (intervention, control) × 2 (pre-intervention, postintervention) analysis of variance test revealed no significant intervention × time interaction effect (F1,38=0.020, P=.889) in the full sample. This effect, however, was significantly moderated by race-ethnicity: Results indicated a significant intervention × time × race interaction (F1,36=8.050, P=.007, partial η2=.183) such that the intervention significantly improved sleep hours (by approximately 1 hour) only among non-Hispanic whites (and not among adolescents of racial-ethnic minority status). CONCLUSIONS: Adolescents from racial-ethnic minority groups may face significant barriers that interfere with their ability to successfully alter their sleep-wake patterns and maximize sleep hours.

Adolescents' technology and face-to-face time use predict objective sleep outcomes.

OBJECTIVES: The present study examined both within- and between-person associations between adolescents' time use (technology-based activities and face-to-face interactions with friends and family) and sleep behaviors. We also assessed whether age moderated associations between adolescents' time use with friends and family and sleep. DESIGN: Adolescents wore an actigraph monitor and completed brief evening surveys daily for 3 consecutive days. PARTICIPANTS: Adolescents (N=71; mean age=14.50 years old, SD=1.84; 43.7% female) were recruited from 3 public high schools in the Midwest. MEASURES: We assessed 8 technology-based activities (eg, texting, working on a computer), as well as time spent engaged in face-to-face interactions with friends and family, via questions on adolescents' evening surveys. Actigraph monitors assessed 3 sleep behaviors: sleep latency, sleep hours, and sleep efficiency. RESULTS: Hierarchical linear models indicated that texting and working on the computer were associated with shorter sleep, whereas time spent talking on the phone predicted longer sleep. Time spent with friends predicted shorter sleep latencies, while family time predicted longer sleep latencies. Age moderated the association between time spent with friends and sleep efficiency, as well as between family time and sleep efficiency. Specifically, longer time spent interacting with friends was associated with higher sleep efficiency but only among younger adolescents. Furthermore, longer family time was associated with higher sleep efficiency but only for older adolescents. CONCLUSION: Findings are discussed in terms of the importance of regulating adolescents' technology use and improving opportunities for face-to-face interactions with friends, particularly for younger adolescents.

Diurnal cortisol slopes and mental and physical health outcomes: A systematic review and meta-analysis.

Changes in levels of the stress-sensitive hormone cortisol from morning to evening are referred to as diurnal cortisol slopes. Flatter diurnal cortisol slopes have been proposed as a mediator between chronic psychosocial stress and poor mental and physical health outcomes in past theory and research. Surprisingly, neither a systematic nor a meta-analytic review of associations between diurnal cortisol slopes and health has been conducted to date, despite extensive literature on the topic. The current systematic review and meta-analysis examined associations between diurnal cortisol slopes and physical and mental health outcomes. Analyses were based on 179 associations from 80 studies for the time period up to January 31, 2015. Results indicated a significant association between flatter diurnal cortisol slopes and poorer health across all studies (average effect size, r=0.147). Further, flatter diurnal cortisol slopes were associated with poorer health in 10 out of 12 subtypes of emotional and physical health outcomes examined. Among these subtypes, the effect size was largest for immune/inflammation outcomes (r=0.288). Potential moderators of the associations between diurnal cortisol slopes and health outcomes were examined, including type of slope measure and study quality indices. The possible roles of flatter slopes as either a marker or a mechanism for disease etiology are discussed. We argue that flatter diurnal cortisol slopes may both reflect and contribute to stress-related dysregulation of central and peripheral circadian mechanisms, with corresponding downstream effects on multiple aspects of biology, behavior, and health.

Perceived morningness-eveningness predicts academic adjustment and substance use across university, but social jetlag is not to blame.

Past research has consistently found that evening-types typically report poorer academic adjustment and higher levels of substance use compared to morning-types. An important development within the morningness-eveningness and psychosocial adjustment literature has been the hypothesis that social jetlag (i.e. the asynchrony between an individual's "biological" and "social" clocks) is one factor that may explain why evening-types are at a greater risk for negative psychosocial adjustment. Yet, only a handful of studies have assessed social jetlag. Furthermore, the few studies that have assessed social jetlag have done so only with concurrent data, and thus have not been able to determine the direction of effects among morningness-eveningness, social jetlag and psychosocial adjustment. To address this important gap in the literature, the present 3-year longitudinal study employed the use of a cross-lagged auto-regressive model to specifically examine the predictive role of perceived morningness-eveningness and social jetlag on two important indices of psychosocial adjustment among university students: academic adjustment and substance use. We also assessed whether there would be an indirect effect between perceived morningness-eveningness and psychosocial adjustment through social jetlag. Participants were 942 (71.5% female; M = 19 years, SD = 0.90) undergraduates at a mid-sized university in Southern Ontario, Canada, who completed a survey at three assessments, each one year apart, beginning in first-year university. Measures were demographics (age, gender and parental education), sleep problems, perceived morningness-eveningness, social jetlag, academic adjustment and substance use. As hypothesized, results of path analyses indicated that a greater perceived eveningness preference significantly predicted higher social jetlag, poorer academic adjustment and higher substance use over time. In contrast, we found no support for social jetlag as a predictor of academic adjustment and substance use, indicating that social jetlag did not explain the link between perceived morningness-eveningness and negative psychosocial adjustment. An important finding was the significant predictive effect of higher substance use on social jetlag over time. Results of the present study highlight the importance of employing a longitudinal framework within which to specifically determine the direction of effects among the study variables in order to validate proposed theoretical models that aim to guide our understanding of how perceived morningness-eveningness, social jetlag, academic adjustment and substance use relate to each other.

Bidirectional associations between sleep (quality and duration) and psychosocial functioning across the university years.

Despite extensive research on sleep and psychosocial functioning, an important gap within the literature is the lack of inquiry into the direction of effects between these 2 constructs. The purpose of the present 3-year longitudinal study was to examine bidirectional associations between sleep (quality and duration) and 3 indices of psychosocial functioning (intrapersonal adjustment, friendship quality, and academic achievement). We also assessed the role of gender as a possible moderator of the patterns of results. Participants were 942 (71.5% female) emerging adults enrolled at a mid-sized university in southern Ontario, Canada, who ranged in age from 17 to 25 years (M = 19.01 years, SD = 0.90) at the first assessment. Students completed surveys in the winter term for 3 consecutive years, beginning in their first year of university. Survey measures included demographics, sleep quality and duration, intrapersonal adjustment (depressive symptoms, stress, and self-esteem), friendship quality, and academic achievement. Results of path analyses indicated a significant bidirectional association between sleep quality and intrapersonal adjustment. We also found evidence for unidirectional associations, such that better friendship quality and higher academic achievement predicted better sleep quality over time. Overall, psychosocial functioning was more strongly associated with sleep quality relative to sleep duration. Our findings highlight the importance of a longitudinal and holistic approach in understanding the link between sleep and psychosocial functioning among emerging adults at university.

Are all evening-types doomed? Latent class analyses of perceived morningness-eveningness, sleep and psychosocial functioning among emerging adults.

An overwhelming amount of research has indicated that evening-types report more negative psychosocial functioning as well as more negative sleep characteristics (e.g. more sleep problems) relative to morning-types. Researchers also find a strong, consistent link between poor sleep characteristics and negative psychosocial functioning. These studies, however, have been based on a variable-centred approach, and thus were not able to assess possible individual differences within morning-types and evening-types with respect to their sleep characteristics prior to assessing differences in psychosocial functioning. Thus, it is not clear whether it is morningness-eveningness per se or sleep characteristics that explain the differences in psychosocial functioning found between morning-types and evening-types. The purpose of the present two-year longitudinal study was to employ a person-centred approach to determine whether there are subgroups within morning-types and evening-types based on 10-sleep characteristics (e.g. sleep problems and sleep duration). Then subgroups were compared on three indices of psychosocial functioning (i.e. academics, intrapersonal adjustment and alcohol consumption), both concurrently, as well as one year later. Participants were 780 (72.2% female; M = 19.0 years, SD = 0.90) emerging adults at a mid-sized university in Southern Ontario, who were either morning-types or evening-types. A latent class analysis (LCA) conducted for morning-types yielded two subgroups, classified as having good sleep characteristics (i.e. morning-good) and poor sleep characteristics (i.e. morning-poor). Results of a second LCA conducted for evening-types yielded three subgroups, classified as having good (i.e. evening-good), moderate (i.e. evening-moderate) and poor (i.e. evening-poor) sleep characteristics. Results comparing subgroups across the 10-sleep characteristics indicated that morning-good and evening-good individuals reported very similar scores, and both were characterized by the least sleep problems and longest sleep duration relative to the other subgroups. In terms of the three psychosocial functioning indices we found that academic achievement generally did not differ across the five subgroups (i.e. morning-good, morning-poor, evening-good, evening-moderate and evening-poor). With respect to intrapersonal adjustment, morning-good and evening-good subgroups reported significantly better intrapersonal adjustment relative to the other subgroups across time. Interestingly, evening-type subgroups generally reported higher alcohol consumption than morning-type subgroups. Overall, these results suggest that intrapersonal adjustment in particular appears to be associated more with differences in sleep characteristics (i.e. sleep problems and duration), than with morningness-eveningness per se, while the opposite is generally true for alcohol consumption. Lifestyle and personality factors likely also play a critical role. Importantly, our study is the first to identify a subgroup of evening-types who report good sleep characteristics and similar levels of intrapersonal adjustment and academic achievement to that of the majority of morning-types.

Adolescent turning points: the association between meaning-making and psychological well-being.

Research findings indicate that the ability to create meaning out of turning points (i.e., significant life experiences) is related to psychological well-being. It is not clear, however, whether individuals who report meaning-making and higher well-being are better adjusted prior to the experience of their turning point event. This study examined whether meaning-making and timing of turning points would be associated with higher scores on well-being. Participants were 418 Grade 12 students (209 of whom reported having had a turning point event and a matched group of 209 adolescents who did not report having had a turning point event). This subset of participants was taken from a larger longitudinal study of 803 (52% female) Grade 12 Canadian students (M age = 17 years). All participants completed well-being measures 3 years prior, when they were in Grade 9. Meaning-making was significantly associated with higher psychological well-being, controlling for Grade 9 scores on well-being. Importantly, adolescents who reported meaning-making in Grade 12 did not differ on well-being prior to the experience of their turning point event, when they were in Grade 9, from adolescents who did not report meaning-making. These findings highlight the importance of examining meaning-making in relation to positive adjustment among adolescents reporting a significant life-changing event. Limitations regarding the use of survey measures and the generalizability of the results to a culturally diverse group of adolescents are discussed.