Abstract
Background: Loneliness is emerging as a key risk factor for child and adolescent mental health. Exacerbated by lack of support, busy routines, continuous adversities, and poor social networks, it is a public health concern. Sleep is essential for healthy development and emotional regulation, critical for modulating risk‑taking, and determines optimal learning and mental health. However, the connection between loneliness and sleep and their impact on mental health and educational outcomes is not well known in low‑ and middle‑income countries (LMICs) like Kenya, where a large portion of the population is young. Objectives: (1) Examine the bidirectional relationship between loneliness and impaired sleep in a Kenyan adolescent cohort. (2) assess the individual and joint contribution of loneliness and sleep impairment relationship in common mental health problems such as anxiety, depression, and anger, while controlling for adverse childhood experiences (ACEs). Methods: A cross‑sectional study with 70 adolescents (ages 11-15) from Nairobi schools. Measures used: Loneliness (NIH Toolbox), Sleep Impairment (PROMIS), Mental Health (PROMIS‑Anger, Anxiety, Depression), ACEs (WHO ACEs‑IQ). Findings: We found a strong association between loneliness and sleep impairment, even after controlling for ACEs (associated with 32.0%-33.9% of variance). Higher ACEs were also associated with increased loneliness and sleep impairment. Notably, after adjusting for the ACE confounder, both sleep impairment and loneliness were significantly associated with adolescent mental disturbances (anxiety, depression, and anger), with sleep impairment explaining greater variance (27.2%-30.4%) than loneliness (11.8%-27.4%) for the anxiety, anger, depression outcomes. Jointly, loneliness and sleep impairment were associated with 28.8%-30.4% of the variance in adolescents' mental health problems. Conclusion: Our article contributes new evidence that sleep health is critical to mental well‑being for adolescents living in high ACEs and LMIC contexts. Providing intervention strategies to reduce loneliness and promote sleep health should be considered to improve adolescent mental health.