Sleep-Related Problems and Problematic Smartphone Use in Young Adult Males: Findings from a Short-Term Behavioral Restriction Study

Purpose: Problematic smartphone use is a prevalent behavioral issue in the digital age and is frequently associated with sleep disturbances. However, evidence on how different sleep domains respond to short-term behavioral restriction under natural conditions remains limited. This study aimed to examine smartphone use patterns in young adult males, evaluate their relationship with problematic smartphone use risk, and assess changes in sleep-related outcomes following short-term, institutionally mandated smartphone restriction. Patients and Methods: This prospective pre-post observational study was conducted at a male police college during a 10-day institution-mandated smartphone restriction. Participants (n = 254) were classified into low-risk and high-risk problematic smartphone use groups based on the Smartphone Addiction Scale-Short Version (SAS-SV). Sleep quality, sleep hygiene, insomnia severity, and daytime sleepiness were measured before and after the restriction period. Associations between smartphone use characteristics (daily duration, timing of use, and usage purposes) and sleep outcomes were examined using group comparisons and multivariate analyses. Results: At baseline, individuals classified as high-risk reported longer overall smartphone use, particularly during evening hours, together with poorer sleep hygiene, lower perceived sleep quality, and greater daytime sleepiness. After the restriction period, improvements were mainly observed in behaviorally related sleep measures, including sleep hygiene and subjective sleep quality. In contrast, insomnia severity and daytime sleepiness showed limited change and did not demonstrate a significant group-by-time interaction. Conclusion: The findings suggest that intensive evening smartphone use may be associated with sleep difficulties that are largely behaviorally mediated. Improvements in sleep-related behaviors accompanied short-term reductions in device exposure, whereas sleep parameters linked to more stable physiological regulation appeared less responsive over this brief interval. Addressing the timing and intensity of smartphone use is a relevant behavioral target in strategies to improve sleep health in young adults.