Abstract
Road crashes are a leading cause of death and disability in adolescence. Various factors can contribute to these crashes including overt risk-taking but also distracted, inattentive, and unfocused driving. Adolescent drivers are likely to be more susceptible to these issues if they experience sleep issues or have symptoms associated with inattention (e.g., ADHD) or cognitive disengagement syndrome (CDS; formerly termed sluggish cognitive tempo). In this study we surveyed 365 teenage drivers aged 16-18 years living in New Zealand. The survey included measures of distracted and unfocused driving, self-reported sleep issues, inattention and CDS. Smartphone use while driving was significantly associated with sleep issues, inattention and CDS symptoms among teens who drive unsupervised, but not those who only drive under supervision (i.e., Learners), whereas unfocused driving was correlated with inattention, CDS and to a lesser extent sleep issues in both groups. Modelling revealed that daytime sleepiness mediated the association between sleep issues and distracted driving for unsupervised drivers, but not supervised learners. In contrast, both inattention and CDS mediated the association between sleep issues and unfocused driving, and these effects were not moderated by unsupervised driving status. However, unsupervised teen drivers reported significantly higher rates of all forms of aberrant driving behaviour than supervised teens. These results highlight that sleep issues are a key risk factor for distracted and inattentive driving among young drivers, and that inattention and CDS symptoms influence unfocused driving.