Bidirectional associations between nightly sleep and daily happiness and negative mood in adolescents
Kouros, Keller, Martin-Pinon & El-Sheikh (2022) published “Bidirectional Associations Between Nightly Sleep and Daily Happiness and Negative Mood in Adolescents” in Child Development. I have written about sleep before, but like this study because it uses both sleep diaries and actigraphy with a relatively diverse sample. Here’s the abstract:
This study examined bidirectional associations between daily happiness and negative mood and subjective and objective sleep measures. Participants were 311 adolescents (Mage = 17.37 years; 51.8% female; 59.2% White/European American, 38.6% Black/African American, 1% Hispanic/Latinx American, 1.4% multi-racial; 19.3% below poverty line) observed over a 7-day period (2017–2018) using sleep diaries and actigraphy. Daily negative mood was related to greater subjective sleep/wake problems, and happiness was related to lower subjective sleep/wake problems. Conversely, shorter self-reported sleep duration was related to higher negative mood the next day. For actigraphy measures, daily negative mood was related to greater sleep duration and efficiency, whereas happiness was related to lower sleep efficiency. Differences in associations based on subjective versus objective sleep measures are discussed.
Kouros et al. begin by noting that “Both short sleep duration and poor sleep quality are predictors of internalizing and externalizing symptoms in adolescence (e.g., El-Sheikh et al., 2020). Although adolescent sleep concerns may be driven by multiple biological and social factors (e.g., puberty-related shifts in circadian rhythms, time spent engaged with social media or on electronic devices; Hysing et al., 2015; Randler, 2008), there is a growing understanding that mood has an important role to play in adolescent sleep. In particular, adolescent sleep may disrupt or itself be disrupted by adolescent mood.”
They then describe “hormonally driven decreases in the rate of build-up of the homeostatic drive for sleep, and a delay in the timing of melatonin responsiveness to light dimming in the circadian process of sleep regulation (Hagenauer & Lee, 2013). Although it takes longer to build in adolescence, the homeostatic drive for sleep dissipates at the same rate as in childhood (Crowley et al., 2018). The consequence is that adolescents experience a shift forward in the preferred timing of their sleep rather than a significant decrease in the amount of sleep needed (Fuligni et al., 2019).” They note a 40% decrease in slow wave sleep which facilitates synaptic pruning and brain reorganization including in the pre-frontal cortex, adding that such pruning is important in emotion regulation (Hare et al., 2008). Furthermore, in adolescence there is also increased amygdala reactivity to emotional stimuli, and difficulties regulating these intense emotional experiences (Casey & Caudle, 2013). As sleep deprivation increases amygdala reactivity and disrupts connections between the amygdala and regions that regulate emotions, sleep may be especially important for adolescent emotional functioning.
They found that the relationship between negative mood and subjective sleep/wake problems that night was stronger among adolescents from racial/ethnic minority groups. Similarly, in lower SES teens, higher than usual subjective sleep/wake problems were associated with higher negative mood the next day.
One interesting finding, counter to their expectation was that “associations involving objective measures of sleep were counter to hypotheses: negative mood was associated with higher sleep efficiency and greater objective sleep minutes and positive mood was associated with lower sleep efficiency.” In their discussion they propose that, “positive mood can be cognitively and physiologically arousing (El-Sheikh & Buckhalt, 2005). A person who is very excited about an event occurring the next day, for example, may have difficulty sleeping that night.” Conversely, sleep may be a compensatory mechanism when a teen has had an unusually bad day.
It’s not surprising, but helpful that they found that, “daily happiness, sleep duration, and sleep efficiency were significantly higher on weekends compared to weekdays, while negative mood and sleep/wake problems were significantly lower on weekends compared to weekdays. As weekdays are school days, it is likely that school start times are curtailing adolescent sleep periods and resulting in shorter sleep duration (Nahmod et al., 2019). Furthermore, peer interactions, teacher interactions, and academic work may be more stressful, frustrating, and distressing than the leisure activities and preferred social interactions that are more likely to occur on weekends (Weinstein & Mermelstein, 2007).”