Pre-pandemic circadian phase predicts pandemic alcohol use among adolescents

Circadian phase in high-school students: weekday-weekend shifts and relationships to other sleep/circadian characteristics

STUDY OBJECTIVES

In a sample of high-school students, (1) to characterize within-person changes in sleep and circadian characteristics from school nights to weekend nights, (2) to examine whether later circadian phase relates to weekday-weekend changes in sleep/circadian characteristics, and (3) to examine correlations between biological and proxy measures of circadian phase.

METHODS

Sample included 95 high-school students reporting at least one drink of alcohol in their lifetime. Participants completed baseline self-report measures, wrist actigraphy for 8 days, and two overnight laboratory visits (Thursday and Sunday) for salivary melatonin sample collection. Circadian phase was calculated as the dim light melatonin onset (DLMO; 4 pg/mL threshold). Proxy circadian phase measures included the Composite Scale of Morningness (CSM), Munich Chronotype Questionnaire (MCTQ), and actigraphy-based midsleep.

RESULTS

Other than nap duration, all examined actigraphy-based sleep characteristics, DLMO, and DLMO-sleep phase angles showed weekday-weekend differences (adjusted p-value < .05). Later mean DLMO was associated with larger weekday-weekend changes in total sleep time (b = 0.39, padjusted = .010). CSM and actigraphy-based midsleep showed small-to-moderate (rho = ~0.3) and moderate (rho = ~0.5) correlations with DLMO, respectively, but chronotype based on the MCTQ was not correlated with DLMO.

CONCLUSIONS

In the largest published sample to date, circadian phase substantially shifted from the school week to weekend, underscoring the "social jetlag" imposed by early school start times. Similarly, teens with the latest circadian phase exhibited the greatest weekend catch-up sleep. Finally, perhaps due to the instability of circadian phase in this context, self-reported proxies for circadian timing were poor approximations of biological circadian phase.

Prospective associations between sleep, sensation-seeking, and mature screen usage in early adolescents: findings from the Adolescent Brain Cognitive Development study

STUDY OBJECTIVES

Early exposure to mature content is linked to high-risk behaviors. This study aims to prospectively investigate how sleep and sensation-seeking behaviors influence the consumption of mature video games and R-rated movies in early adolescents. A secondary analysis examines the bidirectional relationships between sleep patterns and mature screen usage.

METHODS

Data were obtained from a subsample of 3687 early adolescents (49.2% female; mean age: 11.96 years) participating in the Adolescent Brain and Cognitive Development study. At year 2 follow-up, participants wore Fitbit wearables for up to 21 nights to assess objective sleep measures and completed a scale about sensation-seeking traits. At year 3 follow-up, they answered questions about mature screen usage.

RESULTS

Of the sample, 41.8% of the sample reported playing mature-rated video games and 49% reported watching R-rated movies. Sensation-seeking traits were associated with R-rated movie watching 1 year later. Shorter sleep duration, later bedtime, more bedtime variability, and more social jetlag (discrepancy between the mid-sleep on weekdays and weekends) were associated with mature-rated video gaming and R-rated movie watching 1 year later. Sleep duration variability was associated with mature-rated video gaming. There was also an interaction effect: those with higher sensation-seeking scores and shorter sleep duration reported more frequent R-rated movie usage than those with longer sleep duration. Secondary analyses showed bidirectional associations between later bedtimes, more variability in bedtimes, and more social jetlag with mature screen usage.

CONCLUSIONS

Early adolescents with sensation-seeking traits and poorer sleep health were more likely to engage in mature screen usage.

The Relationship Between Intraindividual Sleep-Wake Variability and Mental Health in Adolescents

OBJECTIVE

We investigated the relationship between irregular sleep-wake patterns and other aspects of sleep and mental health among adolescents.

METHODS

Community-based sample of adolescents (n = 200, mean age 16.8; 61.7% female) completed baseline assessment (i.e. sleep quality, daytime sleepiness, depressive symptoms, social anhedonia, problematic alcohol use), and 7-8 consecutive days of wearing wrist actigraphy. Irregular sleep-wake patterns were assessed via two methods, both based on actigraphy, to capture day-to-day irregularity (intraindividual variability, IIV) and weekly irregularity (social jet lag, SJL). The Bayesian variability method was performed to calculate IIV in total sleep time (TST), sleep onset, and offset time. SJL was quantified as the actual difference in the sleep midpoint on school days versus non-school days.

RESULTS

Greater IIV in TST was associated with poorer sleep quality (B = 1.66, 95% CI, 0.14, 3.31, p < .05), and greater depressive symptoms (B = 0.72, 95% CI, 0.17, 1.35, p < .05), while greater IIV in sleep offset time was associated greater depressive symptoms (B = 0.63, 95% CI, 0.03, 1.28, p < .05), and greater problematic alcohol use (B = 0.70, 95% CI, 0.12, 1.35, p < .05), all after adjusting for age, sex, family SES, alcohol drinks, and SJL. No significant association was found with sleep onset time. Greater SJL was associated with poorer sleep quality (B = 0.40, 95% CI, 0.27, 0.54, p < .001) and fewer problematic alcohol uses (B = -0.05, 95% CI, -0.09, -0.00, p < .05), when adjusting for age, sex, family SES, and alcohol drinks.

CONCLUSION

Our findings add to a growing body of research on irregularity in sleep-wake patterns and clinical implications.

Do sleep and circadian characteristics predict alcohol use in adult drinkers?

BACKGROUND

While sleep and circadian rhythms are recognized contributors to the risk for alcohol use and related problems, few studies have examined whether objective sleep and circadian measures can predict future alcohol use in humans, and no such studies have been conducted in adults. This study examined whether any baseline sleep and/or circadian characteristics of otherwise healthy adults predicted their alcohol use over the subsequent 12 months.

METHODS

Participants (21-42 years) included 28 light and 50 heavy drinkers. At baseline, a comprehensive range of self-reported and objective sleep/circadian measures was assessed via questionnaires, wrist actigraphy, and measurement of dim light melatonin onset and circadian photoreceptor responsivity. Following this, the number of alcoholic drinks per week and binge drinking episodes per month were assessed quarterly over the subsequent 12 months. Anticipated effects of alcohol (stimulation, sedation, and rewarding aspects) were also assessed quarterly over the 12 months. Analyses included generalized linear mixed-effects models and causal mediation analysis.

RESULTS

Across the range of measures, only self-reported insomnia symptoms and a longer total sleep time at baseline predicted more drinks per week and binges per month (ps <0.02). There was a trend for the anticipated alcohol effect of wanting more alcohol at the 6-month timepoint to mediate the relationship between insomnia symptoms at baseline and drinks per week at 12 months (p = 0.069).

CONCLUSIONS

These results suggest that in otherwise healthy adults, insomnia symptoms, even if subclinical, are a significant predictor of future drinking, and appear to outweigh the influence of circadian factors on future drinking, at least in otherwise healthy adults. Insomnia symptoms may be a modifiable target for reducing the risk of alcohol misuse.