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Adolescents who get less sleep, go to bed later, and have inconsistent sleep schedules tend to experience more inward-directed distress, such as anxiety and depression. A new study published in npj Mental Health Research indicates that highly variable sleep patterns are also linked to a greater reliance on suppressing emotions, with sleep inconsistency showing an especially strong connection to distress in teenage girls. These findings suggest that establishing stable sleep routines might help support the emotional well-being of adolescents.
Adolescence represents a sensitive developmental phase characterized by the emergence of new emotional challenges and the refinement of emotional coping skills. During this time, many young people begin to experience internalizing symptoms, which are emotional and behavioral difficulties directed inward, such as feelings of anxiety, depression, and social withdrawal. To navigate these feelings, adolescents rely on emotion regulation, a process of managing emotional responses.
Two common strategies for regulating emotion are cognitive reappraisal, which involves reframing a situation to change its emotional impact, and expressive suppression, which involves hiding or inhibiting the outward display of feelings. Physical health behaviors, particularly sleep, play a role in how adolescents manage these emotional processes. A 2026 study of teenagers indicated that later bedtimes and shorter sleep periods are linked to poorer self-control and increased impulsiveness.
Another 2026 study of adolescents suggested that sleep problems and emotional coping strategies influence each other over time, and that these patterns can differ between boys and girls. Much of the past research on adolescent sleep and mental health relies on self-reported survey data, which can sometimes overestimate sleep problems or reflect a person’s perceived sleep quality rather than their actual time asleep.
“Sleep problems and mental-health difficulties are known to influence one another, but much of the existing research relies on parental report or adolescents’ own statements about how they sleep,” explained study authors Andrea N. Goldstein-Piekarski and Sarah Izabel. Goldstein-Piekarski is an assistant professor of psychiatry and behavioral sciences at the Stanford School of Medicine and director of the CoPsyN Sleep Lab, and Izabel is a graduate student at Stanford.
“We wanted to investigate whether different aspects of sleep derived objectively from a Fitbit device were associated with symptoms such as sadness, worry, and anxiety and with the strategies adolescents use to regulate their emotions,” the researchers said.
To explore these questions, the research team analyzed data from 1,371 teenagers, with an average age of 14, participating in the ongoing Adolescent Brain Cognitive Development study. They gathered sleep data using Fitbit devices worn by the participants for up to three weeks. To ensure accuracy, the team only included data from adolescents who had at least three weekdays and one weekend day of usable sleep tracking per week.
The researchers categorized the participants into two groups based on the average amount of sleep they received each night, based on their Fitbit. The short sleep group consisted of adolescents who slept just over seven hours or less, while the non-short sleep group consistently slept more than seven hours.
The authors also calculated sleep duration variability, which measures how much a participant’s sleep length fluctuated from night to night on weekdays, and sleep onset time, which was the average time a participant fell asleep. To assess mental health, the adolescents completed standardized questionnaires. The Brief Problem Monitor measured internalizing symptoms by asking teenagers how often they felt fearful, guilty, self-conscious, or sad, while the Emotion Regulation Questionnaire for Children and Adolescents evaluated how frequently the participants used cognitive reappraisal and expressive suppression to manage their feelings.
The data revealed connections between several sleep measures and emotional distress. Adolescents who slept around seven hours or less reported greater internalizing symptoms than those who slept longer, and later sleep onset times were similarly associated with higher levels of internalizing symptoms.
Inconsistent sleep schedules also played a role in emotional well-being, as higher variability in sleep duration was linked to more internalizing symptoms. The researchers found that this association was stronger in teenage girls than in teenage boys, suggesting that adolescent females might be especially sensitive to irregular sleep patterns.
Sleep irregularity was also linked to expressive suppression. Adolescents with highly variable sleep durations were more likely to report suppressing their emotions, whereas neither short sleep duration nor late sleep onset times were associated with expressive suppression.
“Taken together, these findings emphasize that sleep is important to mental health, but they also show that the relationship is nuanced,” the researchers noted. “It depends on which aspect of sleep and which mental health outcome you examine, as well as factors such as sex.”
When looking at cognitive reappraisal, however, the researchers did not find a relationship with any of the sleep measures. Whether teenagers slept adequately, fell asleep late, or had irregular schedules, their tendency to mentally reframe emotional situations remained unaffected.
“From past literature, we anticipated that a greater tendency to use adaptive emotion regulation strategies, including cognitive reappraisal, would be associated with better sleep, but this was not borne out,” the researchers told PsyPost.
“Cognitive reappraisal is a more complex skill that continues to develop through adolescence, so our older teens may have had relatively stable reappraisal abilities that were less sensitive to short-term sleep patterns,” they explained. “It is also possible that links between sleep and reappraisal emerge over longer periods than the one-week window we assessed.”
The findings are in line with research covered by PsyPost in 2025, which observed that irregular sleep patterns are linked to increased internalizing symptoms in 14-year-olds. The results also align with another study covered by PsyPost in 2025 indicating that poor teen sleep is linked to anxiety and depression, though the new research expands on this by using objective sleep tracking devices instead of self-reported sleep surveys.
The connection between sleep variability and emotion regulation reflects patterns seen in younger children. For example, a study covered by PsyPost in 2024 linked objective sleep variability to emotional regulation difficulties, though that earlier research observed behavioral regulation during frustration tasks in six-year-olds rather than self-reported coping strategies in adolescents.
Broadly, these insights complement research covered by PsyPost in 2025 showing that sleep problems top the list of predictors for teen mental illness within this same nationwide cohort.
But the new study, like all research, includes some caveats.
“Our study looked at sleep and mental health at one point in time in an adolescent’s developmental journey (the average age of our participants was about 14 years old), so we cannot conclude that irregular, shorter, or later sleep causes mental-health difficulties across all of adolescent development,” the researchers noted.
It is possible that irregular sleep causes emotional distress, but it is equally possible that experiencing internalizing symptoms leads to a disrupted sleep schedule.
“Another caveat is that sleep was measured with a consumer wearable device (the Fitbit), which gives us an estimate of sleep behavior based on movement rather than a direct measure of brain activity during sleep, which is more precise,” they said.
“In addition, the group of adolescents included in our study was more likely to include White teens and teens with parents who had education beyond high school, so the findings may not apply equally across all groups of adolescents,” the authors added. This demographic skew means the findings might not fully represent the experiences of adolescents from different socioeconomic or racial backgrounds.
“An important next step is research that follows adolescents over time and across different developmental periods to better clarify the timing of the relationships between sleep and mental health measures,” the researchers said. “For example, we want to learn if changes in sleep variability can predict later changes in emotional well-being for early adolescents (around 10-13 years old) and if these changes are different at different stages of adolescence (middle adolescence (14-17 years old) and late adolescence (18-21 years old)).”
They added that future work should also explore the direction of these associations, including whether emotional difficulties lead to sleep disruptions. “We also need studies that test whether helping adolescents get enough sleep, keep more consistent schedules, and fall asleep earlier can improve emotional symptoms and well-being,” they noted.
“Our study emphasizes that different facets of sleep including sleep duration, sleep duration variability, and sleep timing, are each linked with adolescent mental health,” the researchers concluded. “This is encouraging because these are modifiable sleep behaviors that can be improved. Supporting sustainable sleep routines that include all these aspects of sleep health may be a practical way to support adolescent mental health.”
The study, “Associations between objective sleep duration, sleep duration variability, and sleep onset with emotion regulation and internalizing symptoms in adolescents: findings from the ABCD® study,” was authored by Sarah Sampaio Izabel, Orsolya Kiss, Adam J. Krause, Ethan T. Hunt, Sarahjane L. Dube, Nicholas Allgaier, Alexandra S. Potter, Micah E. Johnson, Hugh Garavan, Fiona C. Baker, and Andrea N. Goldstein-Piekarski.