This Is AuburnElectronic Theses and Dissertations

Sleep, Physical Activity, and Mental Health Among Sexual-Minority, Transgender, and Gender-Diverse Youth




Gillis, Brian

Type of Degree

PhD Dissertation


Human Development and Family Science

Restriction Status


Restriction Type


Date Available



In the face of legislation that curtails the rights and wellbeing of sexual- and gender-minority (SGM) youth, developmental science has a responsibility to investigate SGM health and its protective factors. Sleep is a bellwether of health, indicating how well individuals and communities are doing. Given this, the two studies of this dissertation sought to understand the nature of sleep among SGM youth – how it compares to non-SGM peers, how it functions as a risk and protective factor for mental health, and what behaviors could promote SGM sleep. Using data from the Adolescent Brain Cognitive Development Study, the following measures were obtained for youth at age 12: SGM status by self-report, sleep by objective actigraphy, minority stress (past 12-month discrimination) by self-report, mental health (internalizing symptoms and externalizing behaviors) by parent report, and physical activity by accelerometry. Study I focused on sexual-minority (SM) youth. In models adjusted for sociodemographic characteristics and internalizing (anxious/depressive) symptoms, SM youth had shorter sleep duration, later sleep timing, and more irregularity in sleep duration and timing compared to non-SM peers. However, they also had fewer wake minutes during the night, indicative of better sleep quality. Sleep quality, then, emerged as a moderator of relations between discrimination and externalizing behaviors. For SM youth with fewer wake minutes, there was no relationship between discrimination and externalizing (aggressive/rule-breaking) behaviors, suggestive of a protective role for sleep quality. Sleep did not moderate associations between discrimination and internalizing symptoms. Study II focused on gender-minority (GM) youth. In unadjusted models, GM youth had shorter sleep duration but better sleep quality than non-GM youth, and in models adjusted for sociodemographic variables and internalizing symptoms, GM youth had later sleep timing and more irregularity in duration and timing. Physical activity emerged as a moderator of relations between GM status and sleep duration: at higher levels of physical activity, there was no difference in sleep duration between GM and non-GM youth, suggesting that physical activity could protect GM youth from insufficient sleep. Physical activity did not serve a similar function for sleep quality, timing, or regularity. Across studies, findings increase our understanding of sleep in the lives of SGM youth.