Evaluation of a Brief Sleep Intervention Designed to Improve the Sleep, Mood, and Cognitive Performance of Esports Athletes.

This study evaluated a brief sleep intervention designed to improve the sleep, mood, and cognitive performance of professional electronic sports (esports) athletes from three major esports regions (i.e., Asia, North America, and Oceania). Fifty-six esports athletes from South Korea (N = 34), the United States (N = 7), and Australia (N = 15) completed the study. Participants completed an initial 2-week pre-intervention phase to establish a baseline, followed by a 2-week intervention phase that involved a group sleep education class, 1:1 session with a trained clinical psychologist, and daily biofeedback. A wrist activity monitor and daily sleep diary were used to monitor sleep during both phases, while at pre- and post-intervention, participants completed a battery of sleep and mood questionnaires and underwent cognitive performance testing. Sleep knowledge increased from pre- to post-intervention (d = 0.83 [95% CI −1.21, −0.43], p =< 0.001), while there were modest improvements in sleep diary estimates (i.e., sleep onset latency (Mdiff = −2.9 min, p = 0.02), sleep onset time (Mdiff = −12 min, p = 0.03), and sleep efficiency (Mdiff = 1.1%, p = 0.004)) and wrist activity monitor estimates (i.e., sleep onset time (Mdiff = −18 min, p = 0.01)). Insomnia severity scores decreased significantly (d = 0.47 [95% CI 0.08, 0.84], p = 0.001), while sleepiness scores increased but not meaningfully (d = 0.23 [95% CI −0.61, 0.14], p = 0.025). However, there was no significant change in mood (i.e., depression and anxiety) or cognitive performance scores (i.e., mean reaction time or lapses). Sleep interventions for esports athletes require further investigation. Future research should examine whether a stepped-care model, whereby increasing therapeutic input is provided as needed, can optimize sleep, mood, and cognitive performance outcomes.

Sleep regularity and body mass index: findings from a prospective study of first-year college students.

STUDY OBJECTIVES: Using data from a large, prospective study of sleep in first-year college students, we examined whether students' sleep regularity is associated with body mass index (BMI) and BMI change (∆BMI) during their first college semester. In a subset of participants, we also tested whether dim light melatonin onset (DLMO) phase and DLMO-bedtime phase angle are associated with BMI and ∆BMI. METHODS: Analyses included data from 581 students (mean age = 18.7 ± 0.5 years; 58% female; 48% non-white) who had their height and weight assessed at the start of classes (T1) and end of 9 weeks. Participants completed online daily sleep diaries from which total sleep time (TST) and the sleep regularity index (SRI) were calculated. Among participants who completed a DLMO protocol (n = 161), circadian phase was quantified by DLMO and circadian alignment by DLMO-bedtime phase angle. Data were analyzed with linear regressions that controlled for sex and average TST. RESULTS: Average SRI was 74.1 ± 8.7 (range: 25.7; 91.6). Average BMI at T1 was 22.0 ± 3.5 and participants gained 1.8 ± 2.4 kg (range: -7.2; 11.4); 39% gained 2-5 kg, 8% gained >5 kg. Lower SRI was associated with greater BMI at T1 (B = -0.06 [95% CI: -0.09; -0.02], p = 0.001) but not with ∆BMI (p = 0.062). Average TST was not significantly associated with BMI or ∆BMI, nor were circadian phase and alignment in the subsample (p's > 0.05). CONCLUSIONS: Sleep regularity is an understudied but relevant sleep dimension associated with BMI during young adulthood. Our findings warrant future work to examine longer-term associations between sleep regularity and weight gain.

Promoting Independent Sleep Onset in Young Children: Examination of the Excuse Me Drill.

Background: There is compelling evidence to support behavioral interventions as the first-line approach for bedtime resistance in young children. Among the behavioral treatment options, extinction ("cry it out") has the most extensive empirical support and tends to produce the most rapid gains. There are well known problems with the use of extinction, however, including side effects (extinction burst, spontaneous recovery) and poor acceptance, not to mention that extinction fails to teach children appropriate replacement behaviors (what "to do"). This study introduces a new behavioral sleep intervention, the Excuse Me Drill, designed to address some of the limitations of extinction. The EMD was formally evaluated for the first time using a multiple-baseline research design across four participants with sleep disturbance.Participants: Participants included four children who were clinically referred to outpatient pediatric psychology clinics for the treatment of behavioral insomnia of childhood, and included one 2-year-old female, two 7-year-old females, and one 7-year-old male. All participants had a history of dependent sleep onset at bedtime (i.e., parents remained in the child's bedroom upon sleep onset). Methods: A non-concurrent multiple baseline design across participants was used to experimentally evaluate the effectiveness of the EMD. During baseline, parents collected data on independent sleep onset and disruptive bedtime behaviors, but conducted the bedtime routine as usual. Immediately following baseline, parents implemented the EMD protocol until data indicated that children were consistently initiating sleep independently. Follow-up data were collected to determine the extent to which children continued to initiate sleep independently at bedtime in absence of the EMD. Results: Outcomes were promising as the EMD successfully taught all four children to initiate sleep independently and produced notable decreases in disruptive bedtime behavior. Results were maintained at follow-up for three of four participants. In addition, parents rated the EMD to be a socially acceptable procedure for their children. Conclusions: Results of this study indicate that the EMD was effective in promoting independent sleep onset and reducing disruptive bedtime behavior that maintained over time. The EMD should be considered to be a viable alternative to traditional extinction procedures for pediatric sleep disturbance. Implications for practice, limitations, and direction for future research are discussed.

Does Compression of the Fourth Ventricle Cause Preterm Labor? Analysis of Data From the PROMOTE Study.

BACKGROUND: The technique for the compression of the fourth ventricle (CV4) in the brain has been described as a method of reaching the physiologic centers that reside in its floor and of restoring optimal flow of the cerebrospinal fluid. However, a study published as an abstract in 1992 questioned whether CV4, when applied to pregnant women, could induce uterine contractions and possibly labor. OBJECTIVE: To further examine whether CV4 could induce uterine contractions and labor as part of the osteopathic manipulative treatment (OMT) protocol used in the Pregnancy Research in Osteopathic Manipulation Optimizing Treatment Effects (PROMOTE) study. METHODS: Labor and delivery data collected during the PROMOTE study from 2007-2011 were analyzed. The PROMOTE study was funded by the National Institutes of Health and was a randomized controlled clinical trial that measured the primary outcomes of back-specific functioning and pain in pregnant women aged 18 to 34 years. Participants were randomly divided into 3 groups-usual obstetric care only, placebo ultrasound treatment plus usual obstetric care, and OMT plus usual obstetric care. Study participants were scheduled for 7 treatment visits. Presented data were gathered from labor and delivery records. RESULTS: Four hundred participants were included. No significant differences were identified between treatment groups for the development of high-risk status (P=.293) or preterm delivery (P=.673). Evaluation of high-risk status by preterm delivery for the groups also showed no significant differences between groups (P=.455). CONCLUSION: The application of CV4 as part of an OMT protocol during the third trimester caused neither a higher incidence of preterm labor nor the development of high-risk status.

System for Monitoring User Engagement with Personalized Medical Devices to Improve Use and Health Outcomes.

Medical devices used in a home setting for treating a variety of chronic diseases lack the ability to convey meaningful information to the patients directly about how they are engaging with their devices in real-time. This research is focused on the development of a monitoring system that addresses this need. For this initial design and testing, the research team applied the technology to a positive airway pressure (PAP) system used in the treatment of those suffering from obstructive sleep apnea (OSA). Data from experimental testing showed results of 93.6% accuracy, 98.7% sensitivity, and 90.9% specificity in the monitoring system detecting events that are typical of issues occurring during standard PAP therapy use. Results indicate this technology can be considered as a viable solution for providing more meaningful information to users about their engagement with their prescribed medical devices.

Mechanisms influencing older adolescents' bedtimes during videogaming: the roles of game difficulty and flow.

A relationship between evening technology use and sleep has been established, and models suggest various mechanisms to explain this relationship. Recent updates to these models also suggest the influence of individual difference factors, such that the relationship between technology and sleep varies between young people. Flow is an experience of immersion and time distortion that could vary between adolescents when using technology. The aim of the present study was to investigate the effects of flow on the self-selected bedtimes of adolescents when videogaming. Seventeen older adolescent, experienced videogamers (age = 15.9 ± 0.83 years), played a new videogame on two school-night evenings in a sleep laboratory. Game difficulty was set to "hard" one evening (flow condition) and "easy" on the other evening (disrupted flow). Trait and state flow were measured, along with heart rate during videogaming, and bedtime measured objectively with real-time cameras. An interaction effect for heart rate indicated an elevated heart rate in the easy condition after 150 min of gaming (p < 0.02). No significant differences were found in bedtimes between the easy and hard conditions (p = 0.77). Adolescents high on trait flow played for longer and selected significantly later bedtimes than their low trait flow peers but only for the hard (flow) condition (12:22 AM vs. 10:53 PM, p = 0.004). Similarly, adolescents with high state flow went to bed significantly later than those low on state flow (12:24 PM vs. 10:52 PM, p = 0.001), again only in the hard condition. These findings suggest that individual and situational characteristics may amplify the effects of technology use on the "sleep" of adolescents and provides support for the displacement of bedtime hypothesis.

An approach to understanding sleep and depressed mood in adolescents: person-centred sleep classification.

Depressive mood in youth has been associated with distinct sleep dimensions, such as timing, duration and quality. To identify discrete sleep phenotypes, we applied person-centred analysis (latent class mixture models) based on self-reported sleep patterns and quality, and examined associations between phenotypes and mood in high-school seniors. Students (n = 1451; mean age = 18.4 ± 0.3 years; 648 M) completed a survey near the end of high-school. Indicators used for classification included school night bed- and rise-times, differences between non-school night and school night bed- and rise-times, sleep-onset latency, number of awakenings, naps, and sleep quality and disturbance. Mood was measured using the total score on the Center for Epidemiologic Studies-Depression Scale. One-way anova tested differences between phenotype for mood. Fit indexes were split between 3-, 4- and 5-phenotype solutions. For all solutions, between phenotype differences were shown for all indicators: bedtime showed the largest difference; thus, classes were labelled from earliest to latest bedtime as 'A' (n = 751), 'B' (n = 428) and 'C' (n = 272) in the 3-class solution. Class B showed the lowest sleep disturbances and remained stable, whereas classes C and A each split in the 4- and 5-class solutions, respectively. Associations with mood were consistent, albeit small, with class B showing the lowest scores. Person-centred analysis identified sleep phenotypes that differed in mood, such that those with the fewest depressive symptoms had moderate sleep timing, shorter sleep-onset latencies and fewer arousals. Sleep characteristics in these groups may add to our understanding of how sleep and depressed mood associate in teens.

The impact of sleep and psychiatric symptoms on alcohol consequences among young adults.

OBJECTIVE: Independent lines of research have documented links between psychiatric symptoms and poor sleep quality, psychiatric symptoms and alcohol use, and alcohol use and poor sleep quality. The current study examined the synergistic effect of poor sleep quality and psychiatric symptoms on alcohol-related consequences in heavy-drinking young adults. METHOD: Matriculating college students reporting at least one heavy drinking episode over the first nine weeks of the semester (N=385, 52% female) were categorized as experiencing 'good' (n=280) versus 'poor' sleep quality (n=105) and screening 'positive' (n=203) or 'negative' (n=182) for a psychiatric disorder. Sleep quality was assessed using the Pittsburgh Sleep Quality Index; psychiatric diagnosis was assessed using the Psychiatric Diagnostic Screening Questionnaire; and alcohol-related consequences were assessed using the Brief Young Adult Alcohol Consequences Questionnaire. General linear models were used to examine the main effects and interaction between sleep quality and psychiatric symptoms on alcohol-related consequences. RESULTS: Sleep quality moderated the association between psychiatric screen and alcohol-related consequences among heavy-drinking college students, such that psychiatric symptoms were associated with more alcohol-related consequences in the context of poor sleep quality. CONCLUSIONS: The combination of poor sleep quality and psychiatric symptoms is associated with increased alcohol-related consequences among heavy-drinking college students. Given the significant interaction between these symptoms, healthcare providers are encouraged to screen for the presence of sleep and psychiatric disorders among heavy-drinking young adults and to provide empirically-supported treatments as appropriate.

PROMOTE Study: Safety of Osteopathic Manipulative Treatment During the Third Trimester by Labor and Delivery Outcomes.

BACKGROUND: Few quality data exist on the safety of osteopathic manipulative treatment (OMT) during pregnancy. The Pregnancy Research on Osteopathic Manipulation Optimizing Treatment Effects (PROMOTE) study was a randomized controlled clinical trial that studied the application of an OMT protocol to manage pain and dysfunction in pregnant patients during their third trimester. OBJECTIVE: To evaluate the safety of an OMT protocol applied during the third trimester of pregnancy by analyzing incidence of high-risk status and labor and delivery outcomes. METHODS: In the PROMOTE study, 400 pregnant patients were randomly assigned to 1 of 3 study groups: usual care plus OMT (OMT), usual care plus placebo ultrasound treatment (PUT), or usual care only (UCO). The incidence of high-risk status of participants and outcomes of labor and delivery, including length of labor, fever in mother during labor, operative vaginal delivery, conversion to cesarean delivery, need for forceps or vacuum device, need for episiotomy, incidence of perineal laceration, meconium-stained amniotic fluid, and infants' Apgar scores, were analyzed. RESULTS: Data from 380 participants were studied. High-risk status was less likely to develop in participants who received OMT (95% CI, 0.16-0.91; P=.03). The OMT protocol also did not increase risk of precipitous labor, operative vaginal delivery, conversion to cesarean delivery, need for forceps or vacuum device, need for episiotomy, incidence of perineal laceration, or meconium-stained amniotic fluid when compared with participants in the other 2 groups (P>.05). Of all other maternal outcomes examined, no difference was reported among the 3 treatment groups with the exception of incidence of prolonged labor in the OMT group. Participants receiving OMT had longer durations of labor than participants in the other groups (P=.002). CONCLUSION: These results suggest that the OMT protocol given during the third trimester of pregnancy as applied in the PROMOTE study is safe with regard to labor and delivery outcomes. The increased duration in labor in the OMT group needs further study. (ClinicalTrials.gov number NCT00426244).

Psychometric Evaluation of the PSQI in U.S. College Students.

STUDY OBJECTIVES: Examine the psychometric properties of the PSQI in two U.S. college samples. METHODS: Study I assessed convergent and divergent validity in 866 undergraduates who completed a sleep diary, PSQI, and other sleep and psychosocial measures. Study II assessed PSQI insomnia diagnostic accuracy in a separate sample of 147 healthy undergraduates with and without insomnia. RESULTS: The PSQI global score had only moderate convergent validity with sleep diary sleep efficiency (prospective global measure of sleep continuity; r = 0.53), the Insomnia Severity Index (r = 0.63), and fatigue (r = 0.44). The PSQI global score demonstrated good divergent validity with measures of excessive daytime sleepiness (r = 0.18), circadian preference (r = -0.08), alcohol (r = 0.08) and marijuana (r = 0.05) abuse scales, and poor divergent validity with depression (r = 0.48), anxiety (r = 0.40), and perceived stress (r = 0.33). Examination of other analogous PSQI and sleep diary components showed low to moderate convergent validity: sleep latency (r = 0.70), wake after sleep onset (r = 0.37), sleep duration (r = 0.51), and sleep efficiency (r = -0.32). Diagnostic accuracy of the PSQI to detect insomnia was very high (area under the curve = 0.999). Sensitivity and specificity were maximized at a cutoff of 6. CONCLUSIONS: The PSQI demonstrated moderate convergent validity compared to measures of insomnia and fatigue and good divergent validity with measures of daytime sleepiness, circadian phase preference, and alcohol and marijuana use. The PSQI demonstrated considerable overlap with depression, anxiety, and perceived stress. Therefore, caution should be used with interpretation.

Current Alcohol Use is Associated with Sleep Patterns in First-Year College Students.

STUDY OBJECTIVES: To examine whether differences exist in self-reported sleep patterns and self-reported alcohol use for first-semester college students who do or do not report drinking during the last 6 months (mo) of high school. METHODS: Participants were 878 first-year college students. Students completed a survey in late May/early June about alcohol use and consequences, during the last 6 mo of high school; they later completed a daily record of sleep behavior and alcohol use across the first 9 weeks of the first semester of college. High school drinking status (past 6 mo) was classified as positive (HS-6 mo+) or negative (HS-6mo-) based on any indication of drinking on the May/June survey. Collegiate drinking was determined from first-semester daily diary alcohol reports as non-drinkers (0 reported drinks), drinkers (one or fewer heavy episodic drinking episodes (HED)), and drinkers reporting more than one HED episode. Sleep patterns were compared for non-drinkers, drinkers, and HED with no high school drinking history (HS-6mo-/HED). In addition, a separate analysis compared sleep patterns for college HED with (HS-6mo+/HED) and without (HS-6mo-/HED) high school self-reported alcohol use. RESULTS: Increased alcohol consumption in the first semester of college was associated with later bedtimes and rise times. We found no association of high school alcohol use and sleep in those with collegiate HED. CONCLUSIONS: Later sleep timing in those with greater alcohol use, supports a connection between sleep patterns and alcohol use. Such an early appearance of this connection may herald the development of alcohol use disorder in some individuals.

Digital media use in the 2 h before bedtime is associated with sleep variables in university students.

Digital media use is widespread in University students, and use of digital media near bedtime has a broadly negative effect on sleep outcomes. Adequate and good quality sleep is important for physical and mental health, but few studies have rigorously measured both sleep and digital media use. In this study, we investigated whether self-reported sleep patterns were associated with digital media use in a first-year University student (N = 254, 48% male) population. Students tracked their sleep through daily online diaries and provided digital media use data in 15-min blocks for 2 h prior to bedtime on nine occasions. A longer duration of digital media use was associated with reduced total sleep time and later bedtime, while greater diversity of digital media use was associated with increased total sleep time and earlier bedtime. Analysis of activities in the last hour before bedtime indicated that activity type plays a role in digital media's effect on sleep, with computer work, surfing the Internet, and listening to music showing the strongest relationship to multiple sleep variables. These findings have implications for physical and mental health of University students and can inform design of devices to minimize negative effects of digital media on sleep.

Estimating sleep from multisensory armband measurements: validity and reliability in teens.

Given the recognition that sleep may influence obesity risk, there is increasing interest in measuring sleep parameters within obesity studies. The goal of the current analyses was to determine whether the SenseWear(®) Pro3 Armband (armband), typically used to assess physical activity, is reliable at assessing sleep parameters. The armband was compared with the AMI Motionlogger(®) (actigraph), a validated activity monitor for sleep assessment, and with polysomnography, the gold standard for assessing sleep. Participants were 20 adolescents (mean age = 15.5 years) with a mean body mass index percentile of 63.7. All participants wore the armband and actigraph on their non-dominant arm while in-lab during a nocturnal polysomnographic recording (600 min). Epoch-by-epoch sleep/wake data and concordance of sleep parameters were examined. No significant sleep parameter differences were found between the armband and polysomnography; the actigraph tended to overestimate sleep and underestimate wake compared with polysomnography. Both devices showed high sleep sensitivity, but lower wake detection rates. Bland-Altman plots showed large individual differences in armband sleep parameter concordance rates. The armband did well estimating sleep overall, with group results more similar to polysomnography than the actigraph; however, the armband was less accurate at an individual level than the actigraph.

What Role Does Sleep Play in Weight Gain in the First Semester of University?

We hypothesized that shorter sleep durations and greater variability in sleep patterns are associated with weight gain in the first semester of university. Students (N = 132) completed daily sleep diaries for 9 weeks, completed the MEQ (chronotype) and CES-D (depressed mood) at week 9, and self-reported weight/height (weeks 1 & 9). Mean and variability scores were calculated for sleep duration (TST, TSTv), bedtime (BT, BTv), and wake time (WT, WTv). An initial hierarchical regression evaluated (block 1) sex, ethnicity; (block 2) depressed mood, chronotype; (block 3) TST; (block 4) BT, WT; and (block 5; R(2) change = 0.09, p = 0.005) TSTv, BTv, WTv with weight change. A sex-by-TSTv interaction was found. A final model showed that ethnicity, TST, TSTv, and BTv accounted for 31% of the variance in weight change for males; TSTv was the most significant contributor (R(2) change = 0.21, p < 0.001). Daily variability in sleep duration contributes to males' weight gain. Further investigation needs to examine sex-specific outcomes for sleep and weight.

The link between sleep disturbance and depression among Mexican Americans: a Project FRONTIER study.

OBJECTIVE: To examine the link between disturbed sleep and depression scores in Mexican Americans and non-Hispanic Whites. METHODS: Data were analyzed for 566 participants (45% Mexican Americans) who were part of a rural healthcare study, Project FRONTIER. Mean age was 55.5 years for Mexican Americans (70% female) and 65.6 years for non-Hispanic Whites (69% female). Self-reported sleep disturbance was entered as the predictor, GDS-30 total and factor scores as the outcome variables, and age, sex, education, BMI, and medical diagnoses (hyperlipidemia, diabetes mellitus, and hypertension) entered as covariates. RESULTS: Mexican Americans reported higher rates of sleep disturbances (25%) than non-Hispanic whites (17%). Sleep disturbances were significantly associated with GDS-30 total scores and the factors Dysphoria and Cognitive Impairment in both Mexican Americans and non-Hispanic whites. CONCLUSIONS: In this study, Mexican Americans reported higher rates of sleep disturbances than non-Hispanic whites. Disturbed sleep was positively associated with depression and the factor scores for Dysphoria and Cognitive Impairment in both groups. Given the paucity of research on sleep disorders in Mexican Americans, identifying what sleep disorders are present and the impact treating these sleep disorders have on depression warrant further investigation.

Sex of college students moderates associations among bedtime, time in bed, and circadian phase angle.

Sex differences in circadian rhythms have been reported with some conflicting results. The timing of sleep and length of time in bed have not been considered, however, in previous such studies. The current study has 3 major aims: (1) replicate previous studies in a large sample of young adults for sex differences in sleep patterns and dim light melatonin onset (DLMO) phase; (2) in a subsample constrained by matching across sex for bedtime and time in bed, confirm sex differences in DLMO and phase angle of DLMO to bedtime; (3) explore sex differences in the influence of sleep timing and length of time in bed on phase angle. A total of 356 first-year Brown University students (207 women) aged 17.7 to 21.4 years (mean = 18.8 years, SD = 0.4 years) were included in these analyses. Wake time was the only sleep variable that showed a sex difference. DLMO phase was earlier in women than men and phase angle wider in women than men. Shorter time in bed was associated with wider phase angle in women and men. In men, however, a 3-way interaction indicated that phase angles were influenced by both bedtime and time in bed; a complex interaction was not found for women. These analyses in a large sample of young adults on self-selected schedules confirm a sex difference in wake time, circadian phase, and the association between circadian phase and reported bedtime. A complex interaction with length of time in bed occurred for men but not women. We propose that these sex differences likely indicate fundamental differences in the biology of the sleep and circadian timing systems as well as in behavioral choices.

Epidemiology of insomnia in college students: relationship with mental health, quality of life, and substance use difficulties.

The purpose of this study was to evaluate the prevalence and correlates of insomnia using rigorous diagnostic criteria and a comprehensive assessment battery. In a large sample (N=1,074) of college students (mean age 20.39years), participants were asked to complete a week-long sleep diary and comprehensive questionnaire packet assessing recommended daytime functioning domains (i.e., fatigue, quality of life, depression, anxiety, stress, academic performance, substance use) during the academic year. A significant portion of this sample of college students met proposed DSM-5 criteria for chronic insomnia (9.5%). The chronic insomnia group reported significantly worse sleep, fatigue, depression, anxiety, stress, and quality of life, and greater hypnotic and stimulant use for sleep problems. There were no differences between groups on excessive daytime sleepiness, academic performance, or substance use. This was a rigorous and comprehensive assessment of the prevalence and psychosocial correlates of insomnia. Insomnia is a significant problem in college students and should be regularly assessed. More research is also needed to guide treatment in this population.

Reliability of a Scale Assessing Depressed Mood in the Context of Sleep.

The current study assessed the reliability of Kandel & Davies mood scale with and without sleep-related items. 178 Brown University first-year students (mean age=18.1 years; 108 females) completed online biweekly surveys after weeks 2, 6, 8, and 10 and on 2 consecutive days after weeks 4 and 12 of their first semester. The scale was examined as a 1) full 6-item scale, 2) 5-item scale excluding the sleep item, and 3) 4-item scale excluding the sleep and tired items. Intraclass correlations (ICC) values for consecutive-day assessments and 6 biweekly surveys were similar and not a function of the weeks evaluated. Total-item correlations and inter-measure correlations with the Center for Epidemiologic Studies - Depressed Mood Scale (CES-D) supported the removal of the sleep-related items from the 6-item scale. These analyses confirm the reliability of the original Kandel and Davies depressed mood scale as well as without the sleep-related items.

Circadian phase preference in college students: relationships with psychological functioning and academics.

The current study offers a comprehensive assessment of psychosocial functioning and academic performance in relation to circadian phase preference in a US sample of undergraduate college students (N = 838), aged 17-26 (M = 19.78, SD = 1.89). Women had greater morning preference than men, and seniors had greater morning preference than freshmen. Circadian phase preference, fatigue, perceived stress, depression, anxiety, and substance use were assessed cross-sectionally and grade point average (GPA) was assessed prospectively. Evening phase preference was related to higher levels of fatigue, alcohol and caffeine use, and worse academic performance than morning or intermediate phase preferences.