Holiday and school term sleep patterns of Australian adolescents

Previous research has established that school aged adolescents generally do not obtain enough sleep for their developmental needs. A combination of later and later bedtimes along with wake times that remain constant due to school commitments contributes to this. However, when adolescents have the opportunity, such as during holidays, they tend to sleep for longer and to prefer late bed and wake times. Consequently, teenagers have been described as becoming more “evening typed,” that is, preferring evening activities, and demonstrating a later sleep/wake phase. Besides increased social factors that impact on adolescents’ opportunity for sleep, there is evidence that biological changes during puberty also affect the later timing of sleep. Many adolescents also report poor sleep quality. The consequences of insufficient sleep have been linked with poorer daytime functioning, lower mood, and lower grades. Despite this overall trend for adolescents in general to become more “evening typed”, research suggests that there are still individual differences in adolescents’ preferences for the timing of daily activities and sleep that can be measured by morningness-eveningness scales. Evidence suggests that these preferences are linked to physiological processes within the body that are associated with circadian timing. It has been suggested that adolescents with more of an evening preference are more vulnerable to poorer outcomes in terms of mood, performance, and academic achievement during the school term due to the difficulties they face in scheduling and initiating sleep. This proposed pathway provided the theoretical model on which the present study was based. The current project examined the differences between holiday and school sleep patterns, as well as investigating the complex interrelationships between sleep patterns, sleep quality, circadian preference, substance use, mood, daytime functioning, and grades in a longitudinal study. Three hundred and ten senior students from three secondary schools in metropolitan Melbourne completed both holiday and school time self-report surveys. The aims of the study were to provide information on the sleep patterns of Australian adolescents; to compare sleep patterns at holiday and school time; to ascertain the impact of school term on sleep patterns, mood, and performance; and to investigate whether individual circadian preference played a mediating role in any observed changes.