Journal of Adolescent Health 46 (2010) 124–132 Original article Sleep Patterns and Predictors of Disturbed Sleep in a Large Population of College Students Hannah G. Lund, B.A.a, Brian D. Reider, B.A.b, Annie B. Whiting, R.N.c, and J. Roxanne Prichard, Ph.D.b,* aDepartment of Psychology, Virginia Commonwealth University, Richmond, Virginia bDepartment of Psychology, University of St. Thomas, St. Paul, Minnesota cMassachusetts General Hospital, Boston, Massachusetts Manuscript received March 26, 2009; manuscript accepted June 16, 2009 See Editorial p. 97 Abstract Purpose: To characterize sleep patterns and predictors of poor sleep quality in a large population of college students. This study extends the 2006 National Sleep Foundation examination of sleep in early adolescence by examining sleep in older adolescents. Method: One thousand one hundred twenty-five students aged 17 to 24 years from an urban Midwestern university completed a cross-sectional online survey about sleep habits that included the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale, the Horne-Ostberg Morn- ingness–Eveningness Scale, the Profile of Mood States, the Subjective Units of Distress Scale, and questions about academic performance, physical health, and psychoactive drug use. Results: Students reported disturbed sleep; over 60% were categorized as poor-quality sleepers by the PSQI, bedtimes and risetimes were delayed during weekends, and students reported frequently taking prescription, over the counter, and recreational psychoactive drugs to alter sleep/wakefulness. Students classified as poor-quality sleepers reported significantly more problems with physical and psychological health than did good-quality sleepers. Students overwhelmingly stated that emotional and academic stress negatively impacted sleep. Multiple regression analyses revealed that tension and stress accounted for 24% of the variance in the PSQI score, whereas exercise, alcohol and caffeine consumption, and consistency of sleep schedule were not significant predictors of sleep quality. Conclusions: These results demonstrate that insufficient sleep and irregular sleep–wake patterns, which have been extensively documented in younger adolescents, are also present at alarming levels in the college student population. Given the close relationships between sleep quality and physical and mental health, intervention programs for sleep disturbance in this population should be considered. Ó 2010 Society for Adolescent Medicine. All rights reserved. Keywords: Sleep quality; Sleep disturbance; Adolescence; Stress; Mood; College students Little doubt exists among health professionals about the with an increased risk of work absenteeism and accidents [1],as fundamental importance of sufficient, restorative sleep in main- well as significant decrements in vitality, social functioning, taining one’s physical and mental health. Troubled sleep is physical and mental health, and general quality of life [1–4]. considered both a predictive sign and symptom of many Sleep in younger adolescents (ages 12–17) has been exten- illnesses, and is associated with substantial decrements in the sively documented. Because of a multitude of intrinsic and quality of life. Briefly, chronic sleep disturbances are associated environmental factors, younger adolescents are particularly vulnerable to disturbed sleep, and are one of the most sleep *Address correspondence to: J. Roxanne Prichard, Ph.D., University of deprived age groups in the country [5]. First, pubertal adoles- St. Thomas, 2115 Summit Avenue, JRC LL56, St. Paul, MN 55105. cents experience a biologically based phase change in their E-mail address: [email protected] circadian rhythm that delays sleep and wake onset, making 1054-139X/10/$ – see front matter Ó 2010 Society for Adolescent Medicine. All rights reserved. doi:10.1016/j.jadohealth.2009.06.016 H.G. Lund et al. / Journal of Adolescent Health 46 (2010) 124–132 125 it physically harder to maintain earlier bedtimes [6,7]. and the remaining 3% identified as other or elected not to Second, external factors like increasing caffeine consumption respond. However, there was a female responder bias; and late night use of electronics further delay sleep onset although males and females were enrolled in equal propor- [5,8,9]. Third, early start times for middle schools and high tions, females comprised 63% of the survey respondents. schools demand earlier weekday risetimes [10–12]. Finally, even with sufficient sleep times, adolescents have increased Measures daytime sleepiness and a greater physiological need for sleep compared to prepubertal children, which may result from The online survey included five published scales related to maturational changes in neuronal connectivity [13,14]. sleep, mood, and stress: (a) the Pittsburgh Sleep Quality Index The consequences of this sleep deprivation are severe, (PSQI), (b) the Epworth Sleepiness Scale (ESS), (c) the Horne- impacting adolescents’ physical and mental health, as well Ostberg Morningness Eveningness Scale (MES), (d) the as daytime functioning. Population and clinic-based studies Subjective Units of Distress Scale (SUDS), and (e) the Profile in younger adolescents (ages 11–17) have shown strong asso- of Mood States (POMS). The PSQI differentiates between ciations between chronic sleep restriction and anxiety, ‘‘poor-’’ and ‘‘good-’’quality sleepers by measuring seven depression, and somatic pain [9,15–17]. Younger adoles- areas: subjective sleep quality, sleep latency, sleep duration, cents who report shorter sleep also show decrements in habitual sleep efficiency, sleep disturbances, use of sleep medi- academic performance [5,18], and increased risk-taking cation, and daytime dysfunction over the past month [23]. behaviors including drug use and drowsy driving [9,19].A Scoring is based on a 0–3 Likert scale, where a score of 3 12-month prospective study by Roberts et al. [20] demon- reflects the negative extreme. A global score greater than 5 is strated that insomnia in younger adolescents significantly indicative of a poor-quality sleeper, whereas a score of 5 or increased the risk for subsequent declines in social, psycho- less is indicative of a good-quality sleeper. For this study, logical, physical, and mental health. global PSQI scores were split into three categories: optimal By comparison, fewer studies have examined how sleep (5), borderline (6–7), and poor (8) sleep quality; these cate- patterns change when older adolescents enter college, a time gories were created using the specified cutoff scores for the of minimal adult supervision, erratic schedules, and easy purpose of achieving relatively even group sizes. The internal access to over-the-counter (OTC), prescription, and recrea- consistency of the PSQI, estimated by Cronbach’s alpha, is .73. tional drugs. Of these publications, most have focused on The Epworth Sleepiness Scale is a questionnaire used to sleep patterns, fatigue, and academic performance identify excessive sleepiness associated with accumulated [17,21,22]. Little is known about what factors contribute to sleep debt or clinical sleep disorders [24]. This eight-item scale or exacerbate sleep difficulties in this population. The current assesses how sleepy one has felt in the past 6 months; partic- study measures the extent of sleep deprivation and poor- ipants indicate the likelihood that they would fall asleep while quality sleep in a large population of college students (ages doing certain activities (e.g., watching TV, sitting and talking 17–24), and extends the current literature on adolescent sleep to someone, or stopped at a traffic light), with responses from by examining factors that are both precipitating and perpetu- (0 ¼ would never doze to 3 ¼ high chance of dozing. Scores ating of poor sleep in this age group. Using a multibehavioral range from 0 to 24, with scores over 10 indicative of significant analysis in a nonclinical population, we focused on three main levels of daytime sleepiness. Internal consistency for the ESS, questions: (a) What are the sleep habits of college students? estimated by Cronbach’s alpha, is .75. (b) What behavioral outcomes are associated with poor sleep The Horne-Ostberg Morningness Eveningness Scale is used quality? (c) What physical, emotional, and psychosocial to distinguish between chronotypes (an endogenous character- factors predict poor-quality sleep in college students? istic describing one’s preference for either morning or evening patterns of activity) [25]. Scores range from 16 to 86, corre- sponding to extreme eveningness (lower numbers) to extreme Method morningness (higher numbers). Questions target individual preferences for sleep and wake times, etc., such as: ‘‘Consid- Participants ering only your own ‘feeling best’ rhythm, at what time would Participants were students between the ages of 17 and 24 you get up if you were entirely free to plan your own day?’’ In (N ¼ 1,125; 420 male, 705 female) at a large private univer- response, participants are directed to select a time between the sity in the Midwest. Of these participants, 27% were freshmen hours of 5:00 a.m. and 12:00 p.m. Internal consistency for the (N ¼ 305), 27% were sophomores (N ¼ 312), 24% were MES, estimated by Cronbach’s alpha, is 86. juniors (N ¼ 271), and 20% were seniors (N ¼ 232). The The Subjective Units of Distress Scale is used to assess mean age was 20 (SD ¼ 1.3 years). Survey respondents an individual’s baseline level of stress [26]. Participants indi- were representative of the age and