The influence of smartphone reduction on heart rate variability: a secondary analysis from a randomised controlled trial

A linear multilevel regression indicated HRV significantly declined during the intervention compared to baseline. HRV during the intervention significantly correlated with craving and sleep quality. Conclusions: This may suggest that participants are experiencing a response akin to withdrawal from a behavioural addiction. Importantly, participants reported improved mental wellbeing, suggesting benefits of controlled smartphone use, but our findings provide a deeper insight into the processes underlying reduction in smartphone use and suggest craving and sleep hygiene may be important factors to additionally consider in future studies.<b>Trial registration:</b> ClinicalTrials.gov identifier: NCT06353451.