Mental Health and Sleep Habits/Problems in Children at 3–4 Years of Age: A General Population Study

Abstract Background: Sleep is essential for mental health at all ages, but few studies have investigated the importance of sleep for mental health in early childhood. Therefore, this study examined the association between mental health and sleep habits/problems in children at 3-4 years of age. Methods: Children aged 3 to 4 years who were living in the community (n = 415; 211/204 boys/girls) were recruited in this study. Their mental health was assessed using the Strengths and Difficulties Questionnaire (SDQ), and their sleep habits/problems were evaluated using the Child and Adolescent Sleep Checklist. Results: Based on the total difficulties score of the SDQ, the children were divided into two groups: a poor mental health group (n = 76) and a control group (n = 339). In terms of sleep habits, which included total sleep time, bedtime, wake time, and nap conditions, there were no differences between the two groups. Regarding sleep-related problems, however, anxiety before going to sleep (p = 0.026), abnormality in the circadian rhythm (p = 0.014), and sleepiness during classes outside of naptimes (p = 0.031) were significantly higher in the poor mental health group than in the control group. Multiple regression analysis showed that poor mental health status was significantly associated with sleepiness and snoring (p = 0.017 and p = 0.018, respectively). Conclusions: The mental health status of 3-year-old children is associated with sleep-related problems, namely sleepiness and snoring. Healthcare providers should pay attention to children’s irregular sleep-wake patterns; moreover, interventions for appropriate sleep hygiene will reduce the psychological burden on both children and their families.