Elusive hypersomnolence in seasonal affective disorder: actigraphic and self-reported sleep in and out of depressive episodes.

BACKGROUND: Hypersomnolence has been considered a prominent feature of seasonal affective disorder (SAD) despite mixed research findings. In the largest multi-season study conducted to date, we aimed to clarify the nature and extent of hypersomnolence in SAD using multiple measurements during winter depressive episodes and summer remission. METHODS: Sleep measurements assessed in individuals with SAD and nonseasonal, never-depressed controls included actigraphy, daily sleep diaries, retrospective self-report questionnaires, and self-reported hypersomnia assessed via clinical interviews. To characterize hypersomnolence in SAD we (1) compared sleep between diagnostic groups and seasons, (2) examined correlates of self-reported hypersomnia in SAD, and (3) assessed agreement between commonly used measurement modalities. RESULTS: In winter compared to summer, individuals with SAD (n = 64) reported sleeping 72 min longer based on clinical interviews (p < 0.001) and 23 min longer based on actigraphy (p = 0.011). Controls (n = 80) did not differ across seasons. There were no seasonal or group differences on total sleep time when assessed by sleep diaries or retrospective self-reports (p's > 0.05). Endorsement of winter hypersomnia in SAD participants was predicted by greater fatigue, total sleep time, time in bed, naps, and later sleep midpoints (p's < 0.05). CONCLUSION: Despite a winter increase in total sleep time and year-round elevated daytime sleepiness, the average total sleep time (7 h) suggest hypersomnolence is a poor characterization of SAD. Importantly, self-reported hypersomnia captures multiple sleep disruptions, not solely lengthened sleep duration. We recommend using a multimodal assessment of hypersomnolence in mood disorders prior to sleep intervention.

Sleep influences daily suicidal ideation through affective reactivity to interpersonal events among high-risk adolescents and young adults.

BACKGROUND: Identifying proximal risk factors for suicidal ideation that are modifiable and relevant for adolescents and young adults is critical for suicide prevention. This study used an intensive monitoring approach to examine whether objectively- and subjectively- measured sleep characteristics predict next-day suicidal ideation occurrence and intensity through affective reactivity to interpersonal events in young people at high risk for suicide. METHODS: Participants included 59 (13-23 years; 76% White; 75% female) adolescents and young adults undergoing intensive outpatient program treatment for depression and suicidality. Participants completed daily ratings of suicidal ideation, sleep quality, and affective reactivity to positive and negative interpersonal events for up to 3 months (M = 56 days, SD = 24.13). Actigraphy captured behavioral sleep duration and timing. Multilevel modeling was used to evaluate within-person fluctuations in sleep and affective reactivity as predictors of suicidal ideation, and multilevel mediation tested the indirect effects of sleep on suicidal ideation via affective reactivity to interpersonal events. RESULTS: Results indicate significant indirect effects of objectively measured sleep duration and subjective sleep quality on next-day suicidal ideation via affective reactivity to negative and positive interpersonal events, respectively. Shorter-than-usual sleep predicted the presence and intensity of next-day suicidal ideation via heightened affective reactivity to negative interpersonal events. Worse sleep quality than usual predicted next-day suicidal ideation via reduced affective reactivity to positive interpersonal events. CONCLUSIONS: Affectivity reactivity is a proximal mechanism through which sleep indices may influence risk for suicidal thinking on a daily basis. Findings highlight the utility of targeting sleep and emotion regulation in suicide prevention among adolescents and young adults at high-risk for suicide.

Morning perception of sleep, stress, and mood, and its relationship with overnight physiological sleep: findings from the National Consortium on Alcohol and Neurodevelopment in Adolescence (NCANDA) study.

This cross-sectional study investigated objective-subjective sleep discrepancies and the physiological basis for morning perceptions of sleep, mood, and readiness, in adolescents. Data collected during a single in-laboratory polysomnographic assessment from 137 healthy adolescents (61 girls; age range: 12-21 years) in the United States National Consortium on Alcohol and Neurodevelopment in Adolescence (NCANDA) study were analysed. Upon awakening, participants completed questionnaires assessing sleep quality, mood, and readiness. We evaluated the relationship between overnight polysomnographic, electroencephalographic, sleep autonomic nervous system functioning measures, and next morning self-reported indices. Results showed that older adolescents reported more awakenings, yet they perceived their sleep to be deeper and less restless than younger adolescents. Prediction models including sleep physiology measures (polysomnographic, electroencephalographic, and sleep autonomic nervous system) explained between 3% and 29% of morning sleep perception, mood, and readiness indices. The subjective experience of sleep is a complex phenomenon with multiple components. Distinct physiological sleep processes contribute to the morning perception of sleep and related measures of mood and readiness. More than 70% of the variance (based on a single observation per person) in the perception of sleep, mood, and morning readiness is not explained by overnight sleep-related physiological measures, suggesting that other factors are important for the subjective sleep experience.

Age Trends in Actigraphy and Self-Report Sleep Across the Life Span: Findings From the Pittsburgh Lifespan Sleep Databank.

OBJECTIVE: Sleep changes over the human life span, and it does so across multiple dimensions. We used individual-level cross-sectional data to characterize age trends and sex differences in actigraphy and self-report sleep dimensions across the healthy human life span. METHODS: The Pittsburgh Lifespan Sleep Databank consists of harmonized participant-level data from sleep-related studies conducted at the University of Pittsburgh (2003-2019). We included data from 1065 (n = 577 female; 21 studies) Pittsburgh Lifespan Sleep Databank participants aged 10 to 87 years without a major psychiatric, sleep, or medical condition. All participants completed wrist actigraphy and the self-rated Pittsburgh Sleep Quality Index. Main outcomes included actigraphy and self-report sleep duration, efficiency, and onset/offset timing, and actigraphy variability in midsleep timing. RESULTS: We used generalized additive models to examine potentially nonlinear relationships between age and sleep characteristics and to examine sex differences. Actigraphy and self-report sleep onset time shifted later between ages 10 and 18 years (23:03-24:10 [actigraphy]; 21:58-23:53 [self-report]) and then earlier during the 20s (00:08-23:40 [actigraphy]; 23:50-23:34 [self-report]). Actigraphy and self-report wake-up time also shifted earlier during the mid-20s through late 30s (07:48-06:52 [actigraphy]; 07:40-06:41 [self-report]). Self-report, but not actigraphy, sleep duration declined between ages 10 and 20 years (09:09-07:35). Self-report sleep efficiency decreased over the entire life span (96.12-93.28), as did actigraphy variability (01:54-01:31). CONCLUSIONS: Awareness of age trends in multiple sleep dimensions in healthy individuals-and explicating the timing and nature of sex differences in age-related change-can suggest periods of sleep-related risk or resilience and guide intervention efforts.

Self-reported sleep and circadian characteristics predict alcohol and cannabis use: A longitudinal analysis of the National Consortium on Alcohol and Neurodevelopment in Adolescence Study.

BACKGROUND: Growing evidence indicates that sleep characteristics predict future substance use and related problems. However, most prior studies assessed a limited range of sleep characteristics, studied a narrow age span, and included few follow-up assessments. Here, we used six annual assessments from the National Consortium on Alcohol and Neurodevelopment in Adolescence (NCANDA) study, which spans adolescence and young adulthood with an accelerated longitudinal design, to examine whether multiple sleep characteristics in any year predict alcohol and cannabis use the following year. METHODS: The sample included 831 NCANDA participants (423 females; baseline age 12-21 years). Sleep variables included circadian preference, sleep quality, daytime sleepiness, the timing of midsleep (weekday/weekend), and sleep duration (weekday/weekend). Using generalized linear mixed models (logistic for cannabis; ordinal for binge severity), we tested whether each repeatedly measured sleep characteristic (years 0-4) predicted substance use (alcohol binge severity or cannabis use) the following year (years 1-5), covarying for age, sex, race, visit, parental education, and previous year's substance use. RESULTS: Greater eveningness, more daytime sleepiness, later weekend sleep timing, and shorter sleep duration (weekday/weekend) all predicted more severe alcohol binge drinking the following year. Only greater eveningness predicted a greater likelihood of any cannabis use the following year. Post-hoc stratified exploratory analyses indicated that some associations (e.g., greater eveningness and shorter weekend sleep duration) predicted binge severity only in female participants, and that middle/high school versus post-high school adolescents were more vulnerable to sleep-related risk for cannabis use. CONCLUSIONS: Our findings support the relevance of multiple sleep/circadian characteristics in the risk for future alcohol binge severity and cannabis use. Preliminary findings suggest that these risk factors vary based on developmental stage and sex. Results underscore a need for greater attention to sleep/circadian characteristics as potential risk factors for substance use in youth and may inform new avenues to prevention and intervention.

Neuronal activation and performance changes in working memory induced by chronic sleep restriction in adolescents.

Most adolescents get less than the recommended 8-10 hr of sleep per night. Functional deficits from lack of sleep include disruption of working memory. Adult neuroimaging studies of sleep deprivation suggest diminished responses in task-related brain networks if performance degrades, but compensatory increased responses with maintained performance. This study utilized functional magnetic resonance imaging to examine compensatory and diminished brain responses in adolescents during working memory performance, comparing chronic sleep restriction and healthy sleep duration. Thirty-six healthy adolescents, 14-17 years old, experienced a 3-week protocol: (a) sleep phase stabilization; (b) sleep restriction (~6.5 hr nightly); and (c) healthy sleep duration (~9 hr nightly). After each sleep manipulation, we acquired functional magnetic resonance imaging with an NBack working memory task with four difficulty levels (0 to 3-back). NBack performance degraded with higher task difficulty, but without a detectable effect of sleep duration. ANOVA revealed main effects of both NBack difficulty and sleep in widespread brain networks. Planned contrasts showed that, compared with healthy sleep, sleep restriction resulted in greater medial prefrontal activation and weaker activation in the precuneus for the most difficult task condition. During sleep restriction, we found compensatory functional responses in brain regions that process sensory input and vigilance. However, adolescents also showed impaired performance and diminished brain responses during the hardest task level under a week of chronic sleep restriction. Chronic sleep restriction during adolescence is common. Understanding the impact of ongoing functional compensation and performance breakdown during this developmental period can have important implications for learning and educational strategies.

Higher Rates of Sleep Disturbance Among Offspring of Parents With Recurrent Depression Compared to Offspring of Nondepressed Parents.

OBJECTIVE: Youth who have a parent with recurrent depression are at high risk for mental health problems. There is a need to identify transdiagnostic and clinically actionable mechanisms that explain higher rates of psychopathology among high-risk youth. The present study sought to examine whether offspring of depressed parents exhibit greater parent- and self-reported sleep disturbance, shorter sleep duration, and later sleep midpoint compared to youth without any parental psychopathology. METHOD: Participants included 82 youth, including 41 youth (ages 9-13; mean age = 11.07 years; 46% female) deemed to be at high-risk based on having a parent with a recurrent depression history, and 41 (mean age = 11.16 years; 49% female) at low-risk based on having parents without any history of psychopathology. Youth and their parents completed measures of youth sleep disturbance, and youth completed measures of sleep duration and midpoint using a daily sleep diary for 9 days. RESULTS: Offspring of parents with depression exhibited more sleep disturbance (e.g., problematic nighttime behaviors and daytime sleepiness) than low-risk youth as reported by both parents and youth. For parent-reported sleep disturbance, there were also sex differences. High-risk girls had more sleep disturbance than high-risk boys or low-risk girls. There were no group differences for daily sleep duration and midpoint. CONCLUSION: Sleep disturbance may be an important area for assessment among offspring of parents with depression. Our findings highlight one potential transdiagnostic risk factor that may emerge among high-risk youth, and sex-specific differences in sleep disturbance, which have implications for prevention and intervention.

Social media use predicts later sleep timing and greater sleep variability: An ecological momentary assessment study of youth at high and low familial risk for depression.

INTRODUCTION: Social media (SM) use has been increasingly recognized as a potential contributor to poor sleep. Few studies have examined SM use and sleep using ecological momentary assessment (EMA), compared different types of media use (SM, television, gaming), or examined whether youth at high and low familial risk for depression are differentially affected by SM use. METHODS: The current study included 76 youth (46% female; Mean age = 11.28 years) who were recruited based on parental history of recurrent depression (N = 35 high risk; N = 41 low risk) in the United States. Youth completed a 9-day EMA protocol, which included current activity at time of prompt and daily sleep onset and offset times. Regression and multilevel models were conducted to examine the effects of media use on sleep. RESULTS: Results indicated that youth who used more SM (mean and number of days) went to sleep later, but did not have shorter sleep duration. Youth with more SM use also had higher levels of variability of both sleep timing and sleep duration across the 9-day period. There were no effects of gaming or TV on sleep, and youth at high risk for depression did not have differences in SM use or its effects on sleep compared to low-risk youth. CONCLUSIONS: These findings indicate a unique impact of SM use on sleep timing and variability for youth (regardless of risk status), which may suggest a unique and modifiable pathway through which SM use contributes to poor health.

Sleep and Parasympathetic Activity During Rest and Stress in Healthy Adolescents and Adolescents With Bipolar Disorder.

OBJECTIVE: Sleep disruption contributes to the pathophysiology of mental disorders, particularly bipolar illness, but the biobehavioral mechanisms of this relationship are insufficiently understood. This study evaluated sleep duration, timing, and variability as prospective predictors of parasympathetic nervous system activity during rest and social stress in adolescents with bipolar disorder, reflecting sleep-related interference in stress regulatory systems that may confer vulnerability to mood episodes. METHOD: Participants were adolescents with bipolar disorder (n = 22) and healthy adolescents (n = 27). Sleep duration and timing were measured by actigraphy for 1 week before a laboratory social stress task, during which high-frequency heart rate variability (HF-HRV) was indexed using electrocardiography. Multilevel models were used to evaluate group, sleep characteristics, and their interactions as predictors of initial HF-HRV and change in HF-HRV during rest and stress. RESULTS: Associations between group and changes in HF-HRV during stress were moderated by sleep duration mean (z = 2.24, p = .025) and variability (z = -2.78, p = .006). There were also main effects of mean sleep duration on initial HF-HRV during rest (z = -5.37, p < .001) and stress (z = -2.69, p = .007). Follow-up analyses indicated that, in bipolar adolescents during stress, shorter and longer sleep durations were associated with lower initial HF-HRV (z = -5.44, p < .001), and greater variability in sleep duration was associated with less change in HF-HRV (z = -2.18, p = .029). CONCLUSIONS: Sleep durations that are relatively short or long, which are characteristic of mood episodes, are associated with parasympathetic vulnerability to social stress in adolescents with bipolar disorder. Obtaining regular sleep of moderate duration may favorably affect responses to stress in bipolar youth.

Cognitive control under stressful conditions in transitional age youth with bipolar disorder: Diagnostic and sleep-related differences in fronto-limbic activation patterns.

OBJECTIVES: Adults with bipolar disorder (BD) display aberrant activation in fronto-limbic neural circuitry during cognitive control. However, fronto-limbic response to cognitive control, and factors destabilizing this circuitry, remain under-studied during the transition from adolescence to young adulthood in BD. Sleep patterns are disturbed in BD, undergo change in adolescence, and support brain function. Among transitional age youth, BD diagnosis and sleep (duration and variability) were tested as predictors of fronto-limbic response to a stressful cognitive control task. METHODS: Two groups of youth (13-22 years old) participated: 15 with BD type I, II or not otherwise specified (NOS) [BD; age 18.1 ± 2.7 years (mean ± standard deviation, SD); 17 female] and 25 healthy controls [CTL; age 19.4 ± 2.7 years (mean ± SD); 17 female]. Sleep was monitored with actigraphy for at least 1 week prior to an adaptive multi-source interference functional magnetic resonance imaging (fMRI) paradigm (a Stroop-like cognitive interference task). Group status and sleep duration (average and intra-individual variability) were examined as predictors of activation in response to incongruent>congruent trials within the bilateral amygdala, anterior cingulate (ACC), ventrolateral prefrontal and dorsolateral prefrontal cortical regions of interest. RESULTS: The BD group displayed greater right amygdala activation than the CTL group. Average sleep duration and rostroventral ACC (rvACC) activity were negatively associated in the CTL group, but exhibited a quadratic relationship in the BD group such that short and long sleep were related to greater rvACC activation. Sleep duration variability and dorsal ACC activity were negatively associated in the BD group, and unrelated in the CTL group. Findings remained significant after controlling for age, sex, and mood symptoms. CONCLUSIONS: Subjects with BD displayed a hyper-limbic response during cognitive control, and sleep was a source of variability in ACC engagement. Stabilizing sleep may be one avenue for improving cognitive control in BD.

Eveningness and Later Sleep Timing Are Associated with Greater Risk for Alcohol and Marijuana Use in Adolescence: Initial Findings from the National Consortium on Alcohol and Neurodevelopment in Adolescence Study.

BACKGROUND: Abundant cross-sectional evidence links eveningness (a preference for later sleep-wake timing) and increased alcohol and drug use among adolescents and young adults. However, longitudinal studies are needed to examine whether eveningness is a risk factor for subsequent alcohol and drug use, particularly during adolescence, which is marked by parallel peaks in eveningness and risk for the onset of alcohol use disorders. This study examined whether eveningness and other sleep characteristics were associated with concurrent or subsequent substance involvement in a longitudinal study of adolescents. METHODS: Participants were 729 adolescents (368 females; age 12 to 21 years) in the National Consortium on Alcohol and Neurodevelopment in Adolescence study. Associations between the sleep variables (circadian preference, sleep quality, daytime sleepiness, sleep timing, and sleep duration) and 3 categorical substance variables (at-risk alcohol use, alcohol bingeing, and past-year marijuana use [y/n]) were examined using ordinal and logistic regression with baseline age, sex, race, ethnicity, socioeconomic status, and psychiatric problems as covariates. RESULTS: At baseline, greater eveningness was associated with greater at-risk alcohol use, greater bingeing, and past-year use of marijuana. Later weekday and weekend bedtimes, but not weekday or weekend sleep duration, showed similar associations across the 3 substance outcomes at baseline. Greater baseline eveningness was also prospectively associated with greater bingeing and past-year use of marijuana at the 1-year follow-up, after covarying for baseline bingeing and marijuana use. Later baseline weekday and weekend bedtimes, and shorter baseline weekday sleep duration, were similarly associated with greater bingeing and past-year use of marijuana at the 1-year follow-up after covarying for baseline values. CONCLUSIONS: Findings suggest that eveningness and sleep timing may be under recognized risk factors and future areas of intervention for adolescent involvement in alcohol and marijuana that should be considered along with other previously identified sleep factors such as insomnia and insufficient sleep.

The impact of experimental sleep restriction on affective functioning in social and nonsocial contexts among adolescents.

BACKGROUND: Short sleep duration is highly prevalent in adolescence, and it prospectively predicts problems with emotional adjustment and psychiatric health. To move beyond epidemiological associations and inform models of developmental psychopathology, we experimentally restricted sleep to observe impacts on affective functioning. Based on the importance of social contexts to adolescent emotional experiences, we also examined the impact of restricted sleep on socioaffective functioning in an ecologically valid peer interaction task. METHODS: In Study 1, adolescents (ages 11.5-15.0, n = 48) were randomly assigned to two nights of polysomnography-monitored sleep restriction (4 hr in bed) or extension (10 hr in bed). One week later, they completed the other sleep manipulation. Affective functioning was assessed by self-report and pupil response to standardized affective sounds. Study 2 used a similar protocol and invited adolescents (ages 12-15.0, n = 16) to the sleep laboratory along with 2-4 friends to observe affective behavior in a social context primed for peer conflict. Mixed effects models were used to evaluate the effect of sleep condition on affective outcomes. RESULTS: Study 1 demonstrated increased negative affect following sleep restriction, relative to extension, on self-report (p = .02) and pupil measures (p = .01). Study 2 replicated these effects (both p = .04) and demonstrated greater negative affective behavior in a peer social context (p = .01). Exploratory analyses for positive affect showed reductions as assessed by self-report (p = .005), but not pupil (p = .81), in Study 1; and no significant effects in Study 2 (self-report, p = .14; pupil, p = .29; positive affective behavior, p = .43). CONCLUSIONS: Experimental sleep restriction in adolescence impacts negative affective functioning as evidenced by self-report and pupil reactivity, as well as observed behavior in a social context primed for peer conflict. Implications for the impact of short sleep on developmental trajectories of emotional adjustment and psychiatric health, and opportunities for early intervention, are briefly discussed.

The role of non-rapid eye movement slow-wave activity in prefrontal metabolism across young and middle-aged adults.

Electroencephalographic slow-wave activity (0.5-4 Hz) during non-rapid eye movement (NREM) sleep is a marker for cortical reorganization, particularly within the prefrontal cortex. Greater slow wave activity during sleep may promote greater waking prefrontal metabolic rate and, in turn, executive function. However, this process may be affected by age. Here we examined whether greater NREM slow wave activity was associated with higher prefrontal metabolism during wakefulness and whether this relationship interacted with age. Fifty-two participants aged 25-61 years were enrolled into studies that included polysomnography and a (18) [F]-fluoro-deoxy-glucose positron emission tomography scan during wakefulness. Absolute and relative measures of NREM slow wave activity were assessed. Semiquantitative and relative measures of cerebral metabolism were collected to assess whole brain and regional metabolism, focusing on two regions of interest: the dorsolateral prefrontal cortex and the orbitofrontal cortex. Greater relative slow wave activity was associated with greater dorsolateral prefrontal metabolism. Age and slow wave activity interacted significantly in predicting semiquantitative whole brain metabolism and outside regions of interest in the posterior cingulate, middle temporal gyrus and the medial frontal gyrus, such that greater slow-wave activity was associated with lower metabolism in the younger participants and greater metabolism in the older participants. These results suggest that slow-wave activity is associated with cerebral metabolism during wakefulness across the adult lifespan within regions important for executive function.

Sleep quality predicts future mood symptoms in adolescents with bipolar disorder.

BACKGROUND: Poor sleep is prevalent in adolescents with bipolar disorder, precedes illness onset, and is associated with worse mood symptoms. We examined interrelationships between sleep quality and mood symptoms in adolescents with bipolar disorder, particularly effects of sleep quality on emergent mood symptoms. METHODS: Adolescents with bipolar disorder participated in a two-year longitudinal treatment study. Sleep quality (Pittsburgh Sleep Quality Index, PSQI) was assessed quarterly during treatment (baseline, 3-, 6-, 9-, 12-month visits) and twice during follow-up (18-, 24-month visits). Mood symptoms (ALIFE Psychiatric Status Ratings) were retrospectively rated weekly by an independent clinician. Lag models tested whether sleep quality predicted next month's mood symptoms and whether mood symptoms predicted future sleep quality. RESULTS: Adolescents with bipolar disorder had poor sleep quality. Sleep quality initially improved but remained stable thereafter. Worse sleep quality at 6-months predicted worse depression, hypomania, and suicidal ideation the following month. Sleep quality was worse for adolescents who had a suicide attempt during the study compared to those who did not and was worse preceding months with a suicide attempt compared to months without attempts. Alternatively, worse depression predicted worse future sleep quality at baseline, 3-, and 18-months and worse suicidal ideation predicted worse future sleep quality at baseline, 12-, and 18-months. LIMITATIONS: Mood symptoms were rated retrospectively and the PSQI may not capture all dimensions of sleep important for mood symptoms. CONCLUSIONS: Targeted evidence-based sleep treatment in adolescents with bipolar disorder may alleviate sleep problems and have additional benefits on mood symptoms and suicidality risk.

The role of retinal irradiance estimates in melanopsin-driven retinal responsivity: a reanalysis of the post-illumination pupil response in seasonal affective disorder.

To isolate melanopsin contributions to retinal sensitivity measured by the post-illumination pupil response (PIPR), controlling for individual differences in non-melanopsin contributions including retinal irradiance is required. When methodologies to negate such differences present barriers, statistical controls have included age, baseline diameter, iris pigmentation, and circadian time of testing. Alternatively, the pupil light reflex (PLR) and calculations estimating retinal irradiance both reflect retinal irradiance, while the PLR also reflects downstream pathways. We reanalyzed data from an observational, correlational study comparing the PIPR across seasons in seasonal affective disorder (SAD) and controls. The PIPR was measured in 47 adults in Pittsburgh, Pennsylvania (25 SAD) over 50 seconds after 1 second of red and blue stimuli of 15.3 log photons/cm2/s. The PLR was within 1 second while PIPR was averaged over 10-40 seconds post-stimulus. Two raters ranked iris pigmentation using a published scale. We evaluated model fit using Akaike's Information Criterion (AIC) across different covariate sets. The best-fitting models included either estimated retinal irradiance or PLR, and circadian time of testing. The PLR is collected contemporaneously in PIPR studies and is an individually specific measure of nonspecific effects, while being minimally burdensome. This work extends the prior publication by introducing theoretically grounded covariates that improved analytic model fits based on AIC specific to the present methods and sample. Such quantitative methods could be helpful in studies which must balance participant and researcher burden against tighter methodological controls of individual differences in retinal irradiance.

Circadian photoentrainment varies by season and depressed state: associations between light sensitivity and sleep and circadian timing.

STUDY OBJECTIVES: Altered light sensitivity may be an underlying vulnerability for disrupted circadian photoentrainment. The photic information necessary for circadian photoentrainment is sent to the circadian clock from melanopsin-containing intrinsically photosensitive retinal ganglion cells (ipRGCs). The current study tested whether the responsivity of ipRGCs measured using the post-illumination pupil response (PIPR) was associated with circadian phase, sleep timing, and circadian alignment, and if these relationships varied by season or depression severity. METHODS: Adult participants (N = 323, agem = 40.5, agesd = 13.5) with varying depression severity were recruited during the summer (n = 154) and winter (n = 169) months. Light sensitivity was measured using the PIPR. Circadian phase was assessed using Dim Light Melatonin Onset (DLMO) on Friday evenings. Midsleep was measured using actigraphy. Circadian alignment was calculated as the DLMO-midsleep phase angle. Multilevel regression models covaried for age, gender, and time since wake of PIPR assessment. RESULTS: Greater light sensitivity was associated with later circadian phase in summer but not in winter (ß = 0.23; p = 0.03). Greater light sensitivity was associated with shorter DLMO-midsleep phase angles (ß = 0.20; p = 0.03) in minimal depression but not in moderate depression (SIGHSAD < 6.6; Johnson-Neyman region of significance). CONCLUSIONS: Light sensitivity measured by the PIPR was associated with circadian phase during the summer but not in winter, suggesting ipRGC functioning in humans may affect circadian entrainment when external zeitgebers are robust. Light sensitivity was associated with circadian alignment only in participants with minimal depression, suggesting circadian photoentrainment, a possible driver of mood, may be decreased in depression year-round, similar to decreased photoentrainment in winter.

The association between cortical gyrification and sleep in adolescents and young adults.

STUDY OBJECTIVES: Healthy sleep is important for adolescent neurodevelopment, and relationships between brain structure and sleep can vary in strength over this maturational window. Although cortical gyrification is increasingly considered a useful index for understanding cognitive and emotional outcomes in adolescence, and sleep is also a strong predictor of such outcomes, we know relatively little about associations between cortical gyrification and sleep. We aimed to identify developmentally invariant (stable across age) or developmentally specific (observed only during discrete age intervals) gyrification-sleep relationships in young people. METHODS: A total of 252 Neuroimaging and Pediatric Sleep Databank participants (9-26 years; 58.3% female) completed wrist actigraphy and a structural MRI scan. Local gyrification index (lGI) was estimated for 34 bilateral brain regions. Naturalistic sleep characteristics (duration, timing, continuity, and regularity) were estimated from wrist actigraphy. Regularized regression for feature selection was used to examine gyrification-sleep relationships. RESULTS: For most brain regions, greater lGI was associated with longer sleep duration, earlier sleep timing, lower variability in sleep regularity, and shorter time awake after sleep onset. lGI in frontoparietal network regions showed associations with sleep patterns that were stable across age. However, in default mode network regions, lGI was only associated with sleep patterns from late childhood through early-to-mid adolescence, a period of vulnerability for mental health disorders. CONCLUSIONS: We detected both developmentally invariant and developmentally specific ties between local gyrification and naturalistic sleep patterns. Default mode network regions may be particularly susceptible to interventions promoting more optimal sleep during childhood and adolescence.

Sleep intervention and glycemic control in gestational diabetes mellitus: a feasibility study.

BACKGROUND: Over 50% of pregnant people report poor sleep quality and insomnia, with approximately 25% reporting short sleep (<7 hours per night). Short sleep duration is associated with impaired glucose functioning, insulin resistance, and type 2 diabetes mellitus. Although short sleep is associated with elevated blood glucose in patients with gestational diabetes mellitus, it is not known whether education on healthy sleep habits during pregnancy can improve sleep and thus glycemic control in these patients. OBJECTIVE: We developed a sleep education program specific to pregnancy and targeted to patients with gestational diabetes mellitus. We aimed to evaluate the feasibility of this intervention in the setting of a randomized controlled trial. STUDY DESIGN: A sleep education program specific to pregnancy, "Sleep-4-2," was developed via multidisciplinary collaboration between specialists in maternal-fetal medicine, sleep medicine, and psychiatry. The program was presented to focus groups of pregnant people and a separate group of healthcare providers to gauge acceptability of the program and to modify content. This program was then tested on a group of patients diagnosed with gestational diabetes mellitus. Participants were randomized to a group receiving standard gestational diabetes mellitus care or a group participating in the sleep education program. Baseline demographics, sleep knowledge, and self-reported sleep quality information were obtained from all participants at enrollment and again at 35 weeks of pregnancy. Change in sleep knowledge and quality and degree of glycemic control were compared between groups. RESULTS: Between December 2017 and July 2019, 140 patients were screened and 74 were enrolled in the study and randomized. Recruitment to the study was acceptable, with >50% of eligible approached patients agreeing to participate, and retention in the intervention group was high at 94%. We did not demonstrate any difference in sleep knowledge or in the proportion of patients achieving glycemic control during pregnancy. CONCLUSION: Implementation of a sleep education program specific to pregnancy for patients with gestational diabetes mellitus was feasible in the context of typical care. A definitive trial could be developed on the basis of this pilot study to evaluate whether a sleep intervention in pregnancy can improve glycemic control in patients with gestational diabetes mellitus.

Performance evaluation of the open-source Yet Another Spindle Algorithm sleep staging algorithm against gold standard manual evaluation of polysomnographic records in adolescence.

GOAL AND AIMS: To evaluate an automatic sleep scoring algorithm against manual polysomnography sleep scoring. FOCUS METHOD/TECHNOLOGY: Yet Another Spindle Algorithm automatic sleep staging algorithm. REFERENCE METHOD/TECHNOLOGY: Manual sleep scoring. SAMPLE: 327 nights (151 healthy adolescents), from the NCANDA study. DESIGN: Participants underwent one-to-three overnight polysomnography recordings, one consisting of an event-related-potential paradigm. CORE ANALYTICS: Epoch by Epoch and discrepancy analyses (Bland Altman plots) were conducted on the overall sample. ADDITIONAL ANALYTICS AND EXPLORATORY ANALYSES: Epoch by Epoch and discrepancy analysis were repeated separately on standard polysomnography nights and event-related potential nights. Regression models were estimated on age, sex, scorer, and site of recording, separately on standard polysomnography nights and event-related potential nights. CORE OUTCOMES: The Yet Another Spindle Algorithm sleep scoring algorithm's average sensitivity of 93.04% for Wake, 87.67% for N2, 84.46% for N3, 86.02% for rapid-eye-movement, and 40.39% for N1. Specificity was 96.75% for Wake, 97.31% for N1, 88.87% for N2, 97.99% for N3, and 97.70% for rapid-eye-movement. The Matthews Correlation Coefficient was highest in rapid-eye-movement sleep (0.85) while lowest in N1 (0.39). Cohen's Kappa mirrored Matthews Correlation Coefficient results. In Bland-Altman plots, the bias between Yet Another Spindle Algorithm and human scoring showed proportionality to the manual scoring measurement size. IMPORTANT ADDITIONAL OUTCOMES: Yet Another Spindle Algorithm performance was reduced in event-related-potential/polysomnography nights for N3 and rapid-eye-movement. According to the Matthews Correlation Coefficient, the Yet Another Spindle Algorithm performance was affected by younger age, male sex, recording sites, and scorers. CORE CONCLUSION: Results support the use of Yet Another Spindle Algorithm to score adolescents' polysomnography sleep records, possibly with classification outcomes supervised by an expert scorer.

The association between cortical gyrification and sleep in adolescents and young adults.

Study objectives: Healthy sleep is important for adolescent neurodevelopment, and relationships between brain structure and sleep can vary in strength over this maturational window. Although cortical gyrification is increasingly considered a useful index for understanding cognitive and emotional outcomes in adolescence, and sleep is also a strong predictor of such outcomes, we know relatively little about associations between cortical gyrification and sleep. Methods: Using Local gyrification index (lGI) of 34 bilateral brain regions and regularized regression for feature selection, we examined gyrification-sleep relationships in the Neuroimaging and Pediatric Sleep databank (252 participants; 9-26 years; 58.3% female) and identified developmentally invariant (stable across age) or developmentally specific (observed only during discrete age intervals) brain-sleep associations. Naturalistic sleep characteristics (duration, timing, continuity, and regularity) were estimated from wrist actigraphy. Results: For most brain regions, greater lGI was associated with longer sleep duration, earlier sleep timing, lower variability in sleep regularity, and shorter time awake after sleep onset. lGI in frontoparietal network regions showed associations with sleep patterns that were stable across age. However, in default mode network regions, lGI was only associated with sleep patterns from late childhood through early-to-mid adolescence, a period of vulnerability for mental health disorders. Conclusions: We detected both developmentally invariant and developmentally specific ties between local gyrification and naturalistic sleep patterns. Default mode network regions may be particularly susceptible to interventions promoting more optimal sleep during childhood and adolescence.