Circadian Typology and Sensation Seeking in Adolescents

The circadian system: A neglected player in neurodevelopmental disorders

Patients with neurodevelopmental disorders, such as autism spectrum disorder, often display abnormal circadian rhythms. The role of the circadian system in these disorders has gained considerable attention over the last decades. Yet, it remains largely unknown how these disruptions occur and to what extent they contribute to the disorders' development. In this review, we examine circadian system dysregulation as observed in patients and animal models of neurodevelopmental disorders. Second, we explore whether circadian rhythm disruptions constitute a risk factor for neurodevelopmental disorders from studies in humans and model organisms. Lastly, we focus on the impact of psychiatric medications on circadian rhythms and the potential benefits of chronotherapy. The literature reveals that patients with neurodevelopmental disorders display altered sleep-wake cycles and melatonin rhythms/levels in a heterogeneous manner, and model organisms used to study these disorders appear to support that circadian dysfunction may be an inherent characteristic of neurodevelopmental disorders. Furthermore, the pre-clinical and clinical evidence indicates that circadian disruption at the environmental and genetic levels may contribute to the behavioural changes observed in these disorders. Finally, studies suggest that psychiatric medications, particularly those prescribed for attention-deficit/hyperactivity disorder and schizophrenia, can have direct effects on the circadian system and that chronotherapy may be leveraged to offset some of these side effects. This review highlights that circadian system dysfunction is likely a core pathological feature of neurodevelopmental disorders and that further research is required to elucidate this relationship.

Sensation seeking, drinking motives, and going out mediate the link between eveningness and alcohol use and problems in adolescence

The present study was aimed at obtaining a more comprehensive understanding of the possible mediating factors in the morningness-eveningness → alcohol consumption relation. We explored the role of mediators such as sensation seeking, the frequency of going out in the evenings, and drinking motives. We tested the proposed mediation model via structural equation modeling based on cross-sectional research conducted among Hungarian adolescents and young adults (N = 1695, 42.5% male, Mage = 18.98, SDage = 1.89). The outcomes included the frequency of alcohol consumption and problematic drinking. Both alcohol consumption and problematic drinking were predicted in similar directions and magnitudes by sensation seeking, "going out," and coping drinking motives. However, eveningness still had a significant direct effect on alcohol consumption and problematic drinking after we controlled for sensation seeking, going out, and drinking motives. For problematic drinking, the possible role of drinking motives seems to be higher and more complex than it is for alcohol consumption. The mediators, such as sensation seeking, the amount of time spent out in the evenings, and drinking motives, can explain the eveningness → alcohol consumption relationship and should be targeted for alcohol prevention programs among evening-type adolescents.

Impact of a Behavioral Sleep Intervention in Adolescents With ADHD: Feasibility, Acceptability, and Preliminary Effectiveness From a Pilot Open Trial

OBJECTIVE

An open trial tested the feasibility, acceptability, and preliminary effectiveness of a behavioral sleep intervention in adolescents with ADHD.

METHOD

Fourteen adolescents (ages 13-17 years; 50% male) with ADHD and co-occurring sleep problems received the cognitive-behavioral-based Transdiagnostic Sleep and Circadian Intervention for Youth (TranS-C). Adolescent, parent, and teacher ratings, actigraphy, and daily sleep diaries were collected at pre-intervention, post-intervention, and 3-month follow-up.

RESULTS

Adolescents experienced moderate to large improvements in sleep, mental health symptoms, and daily life executive functioning from pre-treatment to post-treatment, and improvements were generally maintained at 3 months. Pre-intervention, 71.4% of adolescents were classified as poor sleepers and this was reduced to 21.4% and 28.6% at post-treatment and follow-up, respectively.

CONCLUSION

This study provides strong preliminary evidence that TranS-C improves sleep and associated outcomes in adolescents with ADHD and co-occurring sleep problems. A randomized controlled trial is needed to rigorously test the efficacy of TranS-C in this population.

The difference in sleep, depression, anxiety, and Internet addiction between Korean adolescents with different circadian preference

OBJECTIVES

Compared to adults, adolescents tend to prefer evening times developmentally. The orientation toward evening times is associated with behavioral and emotional problems. Thus, this study examined the association of circadian preference with sleep-related variables, depression, anxiety, and Internet addiction in Korean adolescents.

MATERIALS AND METHODS

Participants completed the questionnaires measuring sleep pattern, sleep problem, depression, anxiety, and Internet addiction.

RESULTS

Among 765 students (age range: 13-17 years), 211 students (N _male= 134) were allocated into morning types (MT) and 258 adolescents (N _male= 147) were allocated into evening types (ET) based on scores of the Morningness-Eveningness Scale. Adolescents without circadian preference (N = 296) were defined as neither type (NT). ET, compared to MT and NT, woke up later in the weekend, showed delays in bedtimes, and spent shorter time sleeping. They also reported a higher level of daytime sleepiness, insomnia, and depression than NT. However, the group difference in wake time on school days was not significant, and adolescents showed mild insomnia regardless of their circadian preference. Although smartphone using time in the weekend was significantly different between groups, group difference in Internet addiction was significant only when gender was adjusted.

CONCLUSION

Circadian preference was associated with sleep patterns and sleep problems in Korean adolescents. ET showed significantly different sleep patterns compared to MT and NT. ET not only reported a higher level of daytime sleepiness and insomnia but also more depressive symptoms compared to NT. These findings suggest that the uniqueness of adolescence and environmental factors seemed to influence the association of circadian preference with mental problem.

Salivary Pubertal Hormones, Sleep Disturbance, and an Evening Circadian Preference in Adolescents: Risk Across Health Domains

PURPOSE

Puberty influences biological and psychological development during adolescence. This includes a shift toward an evening circadian preference, which is characterized by greater physical and mental activity at night compared to the morning. This study examines how pubertal hormones are related to risk across key health domains among adolescents with an evening circadian preference.

METHODS

Participants were adolescents with an evening circadian preference (n = 165, 96 female and 69 male, mean age = 14.8) from an NICHD-funded study. Hormones included testosterone, dehydroepiandrosterone (DHEA), and estradiol (females only). Sleep measures included weeknight total sleep time and weeknight bedtime. Circadian preference was assessed with the Children's Morningness-Eveningness Preferences Scale. Health domains included emotional, cognitive, behavioral, social, and physical health.

RESULTS

For female adolescents, estradiol was related to higher risk in the emotional domain. Among female adolescents with later bedtimes, higher estradiol was associated with higher behavioral domain risk (specifically alcohol and substance use). For male adolescents with a more extreme evening circadian preference, higher DHEA and testosterone were associated with higher behavioral domain risk, specifically greater alcohol and substance use or sensation seeking (DHEA only). Among female adolescents with a more extreme evening circadian preference, higher DHEA was associated with greater physical health risk.

CONCLUSIONS

Pubertal hormones may be associated with heightened risk across select health domains. Specifically, higher levels of hormones may contribute to increased risk for alcohol and substance use as well as sensation seeking in the context of an evening circadian preference.

Interactive effects of sleep duration and morning/evening preference on cardiovascular risk factors

Background

Sleep duration and morningness/eveningness (circadian preference) have separately been associated with cardiovascular risk factors (i.e. tobacco use, physical inactivity). Interactive effects are plausible, resulting from combinations of sleep homeostatic and circadian influences. These have not been examined in a population sample.

Methods

Multivariable regression models were used to test the associations between combinations of sleep duration (short [≤6 h], adequate [7-8 h], long [≥9 h]) and morning/evening preference (morning, somewhat morning, somewhat evening, evening) with the cardiovascular risk factors of tobacco use, physical inactivity, high sedentary behaviour, obesity/overweight and eating fewer than 5 daily servings of fruit and vegetables, in a cross-sectional sample of 439 933 adults enrolled in the United Kingdom Biobank project.

Results

Participants were 56% female, 95% white and mean age was 56.5 (SD = 8.1) years. Compared with adequate sleep with morning preference (referent group), long sleep with evening preference had a relative odds of 3.23 for tobacco use, a 2.02-fold relative odds of not meeting physical activity recommendations, a 2.19-fold relative odds of high screen-based sedentary behaviour, a 1.47-fold relative odds of being obese/overweight and a 1.62-fold relative odds of <5 fruit and vegetable daily servings. Adequate sleep with either morning or somewhat morning preference was associated with a lower prevalence and odds for all cardiovascular risk behaviours except fruit and vegetable intake.

Conclusions

Long sleepers with evening preference may be a sleep phenotype at high cardiovascular risk. Further work is needed to examine these relationships longitudinally and to assess the effects of chronotherapeutic interventions on cardiovascular risk behaviours.

Sleep, Circadian Rhythms, and Risk Across Health Domains in Adolescents With an Evening Circadian Preference

Sleep and circadian rhythm changes during adolescence contribute to increased risk across emotional, behavioral, cognitive, social, and physical health domains. This study examines if sleep and dim light melatonin onset (DLMO) are related to greater risk in these 5 health domains. Participants were 163 (93 female, age = 14.7 years) adolescents with an evening circadian preference from a study funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development. Sleep and circadian measures included weekday total sleep time (TST), bedtime, and shut-eye time assessed via sleep diary, the Children's Morningness-Eveningness Preferences scale, and DLMO. Health domains included self-reported emotional, cognitive, behavioral, social, and physical health. Later DLMO was significantly associated with shorter weekday TST, later weekday bedtime, and later weekday shut-eye time, as well as lower risk in the behavioral domain. At the trend level, later DLMO was related to fewer physical health problems. Earlier DLMO combined with a later bedtime, later shut-eye time, or shorter TST predicted greater risk in the cognitive domain. Later DLMO and shorter TST or a later bedtime predicted worse physical health. DLMO timing was not related to the emotional or social domain. There is evidence that a discrepancy between sleep behaviors and the endogenous circadian rhythm may be related to risk in the cognitive domain for adolescents with an evening circadian preference. Preliminary evidence also indicated that a delayed DLMO and shorter TST or a later bedtime may be related to vulnerability to physical health risk.

Smoking, Screen-Based Sedentary Behavior, and Diet Associated with Habitual Sleep Duration and Chronotype: Data from the UK Biobank

BACKGROUND

Sleep duration has been implicated in the etiology of obesity but less is known about the association between sleep and other behavioral risk factors for cardiovascular disease.

PURPOSE

The aim of this study was to examine the associations among sleep duration, chronotype, and physical activity, screen-based sedentary behavior, tobacco use, and dietary intake.

METHODS

Regression models were used to examine sleep duration and chronotype as the predictors and cardiovascular risk factors as outcomes of interest in a cross-sectional sample of 439,933 adults enrolled in the UK Biobank project.

RESULTS

Short sleepers were 45 % more likely to smoke tobacco than adequate sleepers (9.8 vs. 6.9 %, respectively). Late chronotypes were more than twice as likely to smoke tobacco than intermediate types (14.9 vs. 7.4 %, respectively). Long sleepers reported 0.61 more hours of television per day than adequate sleepers. Early chronotypes reported 0.20 fewer daily hours of computer use per day than intermediate chronotypes. Early chronotypes had 0.25 more servings of fruit and 0.13 more servings of vegetables per day than late chronotypes.

CONCLUSIONS

Short and long sleep duration and late chronotype are associated with greater likelihood of cardiovascular risk behaviors. Further work is needed to determine whether these findings are maintained in the context of objective sleep and circadian estimates, and in more diverse samples. The extent to which promoting adequate sleep duration and earlier sleep timing improves heart health should also be examined prospectively.

Chronobiological types, duration of sleeping and psycho-emotional condition of teenagers

Sleep is a biological process that operates according to day and night cycles. This self-regulatory system is universal in all organisms, including humans and mammals. For this reason, the topic is widely analysed in the existing literature; however, no studies about chronobiological types of teenagers have been conducted in Lithuania before. 253 schoolchildren, 13 to 18 years of age, were surveyed in schools of Vilnius and Panevėžys, Lithuania. Responses were gathered during the period from September 2013 to February 2014. The survey consists of four parts: demographical data, Morningness-Eveningness Questionnaire, PedsQL 4.0 survey of life quality, and HADS - Hospital Anxiety and Depression Survey. In total, 115 (45.5%) boys and 138 (54.5%) girls participated in the survey. On average, boys sleep 7.10 (±1.27) hours, compared to 6.79 (±1.20) (p = 0.05) hours for girls. 94 (37.2%) survey participants feel sleepy and/or very sleepy at school. 133 (52.6%) respondents find it difficult/very difficult to wake up in the morning. 218 (86.2%) respondents use the computer before going to sleep: 96 (83.5%) boys and 122 (88.4%) girls. Based on a subjective evaluation, 187 (73.9%) respondents categorize themselves as the evening type and 66 (26.1%) as the morning type. 13 (5.1%) respondents exhibit symptoms of depression. The majority of the respondents categorize themselves as evening/middle chronotypes. The average duration of sleep is 6.93 (±1.24) hours. 86.2% of the respondents use the computer before going to sleep. Half of the children may have difficulties waking up in the morning. One out of three children feels sleepy at school.

CHRONOTYPE ASSOCIATIONS WITH DEPRESSION AND ANXIETY DISORDERS IN A LARGE COHORT STUDY

BACKGROUND

The chronotype, being a morning or an evening type, can influence an individual's psychological health. Studies have shown a link between depressed mood and being an evening type; however, most studies have used symptom scales and not diagnostic criteria, and confounding factors such as sleep patterns and somatic health factors have often not been considered. This study aims to examine the association between chronotype and depressive (major depressive disorder (MDD), dysthymia) and anxiety (generalized anxiety disorder, panic disorder, agoraphobia, and social phobia) disorders diagnosed using clinical interviews, while taking into account relevant sociodemographic, clinical, somatic health, and sleep parameters.

METHODS

Data from a large cohort, the Netherlands Study of Depression and Anxiety were used (n = 1,944), which included 676 currently depressed and/or anxious patients, 831 remitted patients, and 437 healthy controls. Chronotype was assessed using the Munich Chronotype Questionnaire.

RESULTS

Our results showed that current depressive and/or anxiety disorders were associated with a late chronotype (β = .10, P = .004) even when adjusting for sociodemographic, somatic health, and sleep-related factors (β = .09, P = .03). When examining each type of disorder separately, MDD only, but not dysthymia or specific anxiety disorders, was associated with the late chronotype. The late chronotype also reported significant diurnal mood variation (worse mood in the morning).

CONCLUSIONS

Our findings show a clear association between MDD and late chronotype (being an evening type), after controlling for a range of pertinent factors. A late chronotype is therefore associated with a current status of MDD and deserves the relevant clinical attention when considering treatments.

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.

Effects of Chronotype and Synchrony/Asynchrony on Creativity

Individual differences in morningness/eveningness are associated with measures of personality and performance. Yet, little is known about the relationship between morningness/eveningness and creativity. We tested N = 163 participants in the morning or in the evening, using the Composite Scale of Morningness and subtests of the Berlin Model of Intelligence Structure (BIS) Test to measure creativity. Creativity composite scores were derived for fluidity, that is the number of responses, and flexibility, that is the diversity of responses. Morningness was significantly associated with higher fluidity scores. Flexibility scores were positively, but not significantly related to morningness. We observed no significant effects of testing time or synchrony/asynchrony. In a linear regression model, older age, female sex, and higher morningness preference significantly predicted fluidity, indicating that morning types produce more creative solutions than evening-orientated individuals, independent of time of testing. Future studies should aim at replicating this result in larger samples and across other measures of creativity.

Age, sex and personality in early cannabis use

Previous studies analysing personality and cannabis use in adult samples suggest that cannabis users show significant higher levels of impulsivity, sensation seeking and schizotypy. However, there are few studies exploring this relationship in adolescence using psychobiological models of personality. Given the relevance of identifying individual differences that lead adolescents to early cannabis use to prevent future health problems, the present study aimed to explore the relationship between age, sex, personality and early cannabis use using a psychobiological model of personality in a sample of 415 students (51.8% boys) from 12 to 18 years. Chi(2) tests showed significant higher prevalence of cannabis use in boys and in the group aged 15-18 years. Multiple analysis of variance showed significant higher scores in psychoticism, sensation seeking and in all its subscales in cannabis users group, while an interaction with age was found for extraversion and neuroticism: cannabis users scored higher than non-users in the youngest group (12-14 years) but lower in the oldest group in both dimensions. Finally, regression analysis showed that narrower traits of sensation seeking (experience seeking and disinhibition) were the most associated to early cannabis use. Results are discussed in terms of early cannabis users' personality profiles and in terms of the self-medication theory.

Advancing a biopsychosocial and contextual model of sleep in adolescence: a review and introduction to the special issue

Sleep problems in adolescence have been identified as an international public health issue. Over the past few decades, notable advances have been made in our understanding of the patterns and consequences of sleep in adolescence. Despite these important gains, there is much about the role of sleep in adolescence that remains to be understood. This Special Issue brings together studies that examine sleep as it specifically pertains to adolescent development and adjustment. In this introductory article, we argue for the importance of grounding the study of sleep and adolescence in developmental science and a developmental psychopathology framework. First, a review of the literature is used to outline a biopsychosocial and contextual model of sleep in adolescence. Second, attention-deficit/hyperactivity disorder (ADHD) is used as an exemplar of the proposed model given the pervasiveness of sleep problems among youth with ADHD and the likelihood that sleep problems and ADHD symptoms are interconnected in complex ways. Finally, a brief introduction to the empirical articles included in the Special Issue is provided, with particular attention given to how these articles fit within the proposed biopsychosocial and contextual model. Along with the framework proposed in this article, the studies included in this Special Issue advance the current literature and point to critical directions for future research.

Eveningness is Associated with Higher Risk-Taking, Independent of Sex and Personality

This study tested the hypotheses that eveningness is associated with higher risk-taking propensities across different domains of risk and that this association is not the result of sex differences or confounding covariation with particular personality traits. Study participants were 172 men and women between 20 and 40 years of age. Surveys assessed chronotype, domain-specific risk-taking and risk-perception, and Big Five personality dimensions. Eveningness was associated with greater general risk-taking in the specific domains of financial, ethical, and recreational decision making. Although risk-taking was associated with both risk perception and some personality dimensions, eveningness predicted risk-taking independent of these factors. Higher risk-taking propensities among evening types may be causally or functionally linked to their propensities for sensation- and novelty-seeking, impulsivity, and sexual promiscuity.

Circadian preference and trait impulsivity, sensation-seeking and response inhibition in healthy young adults

Circadian preference has been considered related with impulsivity. The purpose of the present study was to evaluate the relationship between circadian typology and impulsivity measured by the Barratt Impulsivity Scale (BIS), sensation-seeking measured by the Sensation Seeking Scale - Form V (SSS-V) and response inhibition elicited by the GO/NO-GO paradigm. A total of 503 Korean healthy college students (288 males and 215 females) completed the Composite Scale of Morningness (CSM) for circadian typology and the BIS and SSS-V for impulsivity and risk taking, respectively. A subset of 142 subjects additionally performed the computerized GO/NO-GO task for motor response inhibition. A significant association was found between the circadian typology of the CSM and impulsivity of the BIS and disinhibition of SSS-V. In addition, there was a difference in trend level between the circadian typology and response inhibition elicited by the GO/NO-GO test. Regarding circadian preference, evening types were significantly associated with higher impulsivity on the BIS, disinhibition on the SSS-V and lower rate of successful inhibition on the GO/NO-GO task compared to morning types. The present results showed significant relationships between circadian preference and impulsivity and sensation-seeking personality traits. In particular, our findings suggest that high impulsivity, disinhibition and impaired response inhibition are more related to evening types. Circadian preference might be associated with psychiatric problems interacting with some aspects of personality traits such as inhibitory control.

Social jetlag negatively correlates with academic performance in undergraduates

Discrepancies between sleep timing on workdays and weekends, also known as social jetlag (SJL), affect the majority of the population and have been found to be associated with increased health risk and health-impairing behaviors. In this study, we explored the relationship between SJL and academic performance in a sample of undergraduates of the Semmelweis University. We assessed SJL and other sleep-related parameters with the Munich ChronoType Questionnaire (MCTQ) (n = 753). Academic performance was measured by the average grade based on weekly test results as well as scores acquired on the final test (n = 247). The average mid-sleep point on free days in the Hungarian sample fits well the regression line plotted for longitudes within the Central European Time Zone and chronotypes, confirming that sunlight has a major impact on chronotype. Multivariate analysis showed negative effect of SJL on the weekly average grade (p = 0.028, n = 247) during the lecture term with its highly regular teaching schedules, while this association disappeared in the exam period (p = 0.871, n = 247) when students had no scheduled obligations (lower SJL). We also analyzed the relationship between the time of the weekly tests and academic performance and found that students with later sleep times on free days achieved worse in the morning (p = 0.017, n = 129), while the inverse tendency was observed for the afternoon test-takers (p = 0.10, n = 118). We did not find significant association between academic performance and sleep duration or sleep debt on work days. Our data suggest that circadian misalignment can have a significant negative effect on academic performance. One possible reason for this misalignment is socially enforced sleep times.

Association between morningness-eveningness and the severity of compulsive Internet use: the moderating role of gender and parenting style

BACKGROUND

Eveningness and Internet addiction are major concerns in adolescence and young adulthood. We investigated the relationship between morningness-eveningness and compulsive Internet use in young adults and explored the moderating effects of perceived parenting styles and family support on such relationships.

METHODS

The participants consisted of 2731 incoming college students (men, 52.4%; mean age, 19.4±3.6years) from a National University in Taiwan. Each participant completed the questionnaires, which included the Morningness-Eveningness Scale (MES), the Yale-Brown Obsessive Compulsive Scale modified for Internet use (YBOCS-IU), the Parental Bonding Instrument for parenting style, the Family Adaptation, Partnership, Growth, Affection, and Resolve questionnaire (APGAR) for perceived family support, and the Adult Self-Report Inventory-4 (ASRI-4) for psychopathology. The morning (n=459), intermediate (n=1878), and evening (n=394) groups were operationally defined by the MES t scores.

RESULTS

The results showed that eveningness was associated with greater weekend sleep compensation, increased compulsive Internet use, more anxiety, poorer parenting styles, and less family support; additionally, the most associated variables for increased compulsive Internet use were the tendency of eveningness, male gender, more anxiety symptoms, less maternal affection/care, and a lower level of perceived family support. The negative association between the morning type and compulsive Internet use severity escalated with increased maternal affection/care and decreased with increased perceived family support. The positive association between the evening type and compulsive Internet use severity declined with increased maternal protection. However, the father's parenting style did not influence the relationship between morningness-eveningness and compulsive Internet use severity.

CONCLUSIONS

Our findings imply that sleep schedule and the parental and family process should be part of specific measures for prevention and intervention of compulsive Internet use.