Nonrestorative Sleep Mediates the Influence of Adverse Childhood Experiences on Psychological Distress, Physical Health, Mental Health, and Activity Limitation: A Longitudinal Study for the General Population in Japan

Background: This study explores the associations between adverse childhood experiences (ACEs), health problems, and increased daytime inactivity, emphasizing nonrestorative sleep (NRS), a subjective perception of unrefreshing sleep, as a significant contributing factor. Methods: A longitudinal online survey utilizing data from the Japan COVID-19 and Society Internet Survey was employed. The Kessler distress scale (K6) served as the primary outcome measure, with a score of K6 ≥ 13 indicating psychological distress. Health-Related Quality of Life-4 was utilized to assess mentally unhealthy days, physically unhealthy days, and days with activity limitation, indicating mental health problems, physical health problems, and daytime inactivity if exceeding 14 days monthly, respectively. NRS frequency within the past 30 days was evaluated on a 5-point scale, with "usually" (16 days or more) indicating NRS presence. ACEs were identified when four or more items from a validated ACEs list were selected. A causal mediation analysis was performed. Results: Among the 17,042 participants, 52.8% were male, averaging 50.35 years of age (SD = 17.73). Approximately 11.1% reported four or more ACEs. Notably, 16.7% met NRS criteria, while 9.6% met psychological distress criteria. The proportions of individuals with physical health problems, mental health problems, and activity limitations were 6.4%, 6.2%, and 4.2%, respectively. Significant mediational pathways via NRS were observed from ACEs to psychological distress (RR = 1.14, 95% CI = 1.08–1.19, p < 0.001), physical health problems (RR = 1.30, 95% CI = 1.21–1.40, p < 0.001), mental health problems (RR = 1.20, 95% CI = 1.13–1.28, p < 0.001), and daytime inactivity (RR = 1.27, 95% CI = 1.17–1.37, p < 0.001). Conclusion: This study suggests that NRS mediates the impact of ACEs on mental or physical health issues and daytime inactivity. Further research is needed to determine whether targeting NRS can alleviate ACE-associated health problems.