Drivers with Attention Deficit Hyperactivity Disorder (ADHD) have been considered to have a 3–4 times higher crash risk than control drivers without ADHD. A core issue which has not been properly dealt with is the role of comorbid diagnoses which frequently appear together with ADHD, especially Oppositional Defiant Disorder (ODD) and Conduct Disorder (CD), sometimes generically referred to as “conduct problems”. The increased crash risk associated with ADHD diagnosis presented in the literature is often based on studies performed with participants with more than one diagnosis. This means that the comorbidity may be high and, consequently, the effect of ADHD on traffic safety may be overestimated. This has been shown in a meta-analysis presenting a relative risk of 1.30 instead.

The existing research on drivers with ADHD is unsatisfying when it comes to methodology, specifically concerning inclusion and exclusion criteria for participants. This has led to a misunderstanding of the driving ability for people with ADHD, which has been cited and spread in the literature for two decades. People with ADHD diagnosis might suffer from this misinterpretation and the specific effects of ADHD on driving behavior remain unclear. There is a potential for better control for confounding factors, for exposure (mileage) and for comorbidity, especially CD and ODD.

The aim of this study was to examine differences in driving behavior between experienced drivers with and without ADHD, respectively.