Do Pharmaceuticals Improve Driving in Individuals with ADHD? A Review of the Literature and Evidence for Clinical Practice

Attention-deficit/hyperactivity disorder (ADHD) is defined as a disorder of impaired attention and/or behavioral control. Studies suggest that the condition can dispose individuals to a higher risk of automobile accidents. ADHD symptoms respond to pharmacotherapy in a majority of uncomplicated cases. Evidence on how pharmacotherapies for ADHD impact driving behavior or outcomes could allow clinicians to support on-road safety rationally. We therefore undertook a review to identify the evidence base to date indicating positive or negative effects of pharmacotherapies on driving behavior in individuals with ADHD. Further, we evaluated the level of evidence for these effects, their specificity to ADHD, and how they may inform clinical care. We identified studies involving pharmacotherapy for ADHD that evaluated driving-related activities or outcomes. We then categorized these studies by the mode of measurement used and by the ADHD specificity of the driving behaviors measured. Finally, we extracted themes of interest to clinical practice in pharmacologic intervention. In total, 14 studies, involving 2-61 subjects diagnosed with ADHD, looked at computer-measured, observer-measured, or self-reported driving behavior correlates of pharmacotherapy during simulation or on-road driving. Of these studies, 13 involved psychostimulant agents and two used atomoxetine. All but three investigations (one of methylphenidate, one of mixed amphetamine salts, and one of atomoxetine) found favorable changes in measures such as steering and braking behaviors or reaction to unexpected events. One study found adverse effects on driving at hour 17 following mixed amphetamine salt administration. Four studies compared two pharmacotherapies, and each found differences in measured driving behavior between the therapies. One study explored impact on ADHD-specific driving impairments, and the same study was the only one to explore correlation of clinical measures (ADHD symptoms and self-reported driving behavior) with medication-associated changes-finding dissociation between changes in ADHD symptoms and changes in measured driving measures. While data to date are limited on the ADHD-specific effects of pharmacotherapies used for ADHD on driving, it is clear from our review that these agents have effects on driving-relevant behaviors. Further research is urgently needed to develop an evidence base for clinically predictable effects of pharmacotherapy on driving safety in individuals with ADHD. If possible, clinicians should evaluate the positive and negative effects of pharmacotherapy on driving in their clients.