Morningness–eveningness and daytime functioning in university students: the mediating role of sleep characteristics

Abstract

SUMMARYThe aim of this study was to explore the mediating role of sleep characteristics in the relationship between morningness-eveningness and three different aspects of daytime functioning: daytime sleepiness, depressive mood and substance use in university students. A multiple mediator model was proposed with sleep debt, poor sleep quality and bedtime delay at weekends as parallel mediators in these relationships. We analysed the data of 1052 university students aged 18-25 years who completed a modified version of the School Sleep Habits Survey, which included questions on sleep and the Composite Scale of Morningness, Sleepiness Scale, Depressive Mood Scale and Substance Use Scale. Students with more pronounced eveningness reported greater daytime sleepiness, greater depressive mood and more frequent substance use, as well as greater sleep debt, poorer sleep quality and greater bedtime delay at weekends. Mediation analyses indicated that morningnesseveningness affected daytime sleepiness and substance use both directly and indirectly through all proposed sleep-related mediators. However, the effect of morningness-eveningness on depressive mood was entirely indirect and was accounted for more by poor sleep than by sleep debt or bedtime irregularity. In conclusion, there are multiple possible mechanisms through which morningness-eveningness affects daytime functioning in university students, and sleep characteristics are a significant mechanism. Sleep debt, poor sleep quality and bedtime irregularity can, to a significant extent, explain the feeling of daytime sleepiness and greater substance use in students with eveningness preferences. However, more depressed mood in the evening-orientated students is primarily a consequence of their poor sleep quality.

Influence of Sleeping Patterns in Health and Academic Performance Among University Students

“…The test-retest reliability of this single-item scale has been estimated at 0.75 across four weeks [51]. The measure has been correlated with hypothetically related variables, thus providing some evidence of construct validity [45]. Using the International Classification of Sleep Disorders, 2nd edition criteria [52], individuals who reported more than one nightmare per week (Option 7, "several times a week") formed a group with a high probability of presenting sleep disorders related to nightmares.…”

“…Whilst it has been reported that women obtain higher scores on morningness [41,42], other studies have indicated that the morning cycle is more frequent in men and the evening pattern more frequent in women [43]. It is indicated that the chronotypic influence, together with a probable gender difference in the neurophysiological substratum of emotional processing, can give rise to the differential appearance of nightmares for women with the eveningness chronotype [44].Further, university students are associated with a preference for eveningness, associated with lower academic performance [45]. A recent meta-analysis of circadian preference and academic achievement showed that evening-orientated students were related to worse academic performance [46].…”

“…Further, university students are associated with a preference for eveningness, associated with lower academic performance [45]. A recent meta-analysis of circadian preference and academic achievement showed that evening-orientated students were related to worse academic performance [46].…”

Personal sleep debt and daytime sleepiness mediate the relationship between sleep and mental health outcomes in young adults

“…Compared to other chronotypes, young adult evening‐types at university also report greater daytime sleepiness (Fernández‐Mendoza et al., ). But unlike sleep debt (Bakotic et al., ), sleepiness was not found to explain mental health symptoms among non‐student young adult evening‐types (Simor, Zavecz, Palosi, Torok, & Koteles, ). The mediating role of sleepiness in the relationship between sleep (e.g., eveningness, sleep duration) and mental health is therefore unclear and has not been specifically investigated among university students.…”

“…Consequently, a large proportion (70%) of university students sleep less than 8 hr (Lund, Reider, Whiting, & Prichard, ) and report increased evening preferences (Kabrita, Hajjar‐Muca, & Duffy, ). Greater sleep debt has been shown to explain the relationship between eveningness and depressive symptoms in university students (Bakotic, Radosevic‐Vidacek, & Koscec Bjelajac, ). Additionally, up to 50% of university students report daytime sleepiness (Lund et al., ; Oginska & Pokorski, ), which associates with increased risk of depression (Nyer et al., ; Regestein et al., ) and anxiety among students (Choueiry et al., ).…”