Attention deficit hyperactivity disorder (ADHD) or syndrome (ADHS) is a symptomatically defined condition that - if untreated - is linked to a significantly increased risk of traffic accidents. In a recent umbrella review, where data from reviews and meta-analyses on 21.142.129 adults was assessed, a pooled prevalence of 3.1% of ADHD in adults was estimated. Considering that globally around 1.35 million people lose their lives and more than 50 million are suffering from injuries or disabilities due to road accidents, the fraction of car accidents caused by ADHD as a risk factor is considerable and needs to be addressed. This risk is largely presumed to be caused by an elevated level of inattentiveness in affected persons.

Compounds of different groups, which can be classified in stimulants - formulations of methylphenidate and amphetamine - and non-stimulants - atomoxetin, guanfacine and clonidine -, have been shown to be effective in alleviating negative effects of ADHD, including inattentiveness. Under well-established but individually managed medication regimes, affected individuals can consequently lead a largely "unirritated" life and are not subject to fundamental restriction with respect to driving anymore.

In children and adolescents, documented negative effects of stimulant medication include loss of appetite and decreased growth rates. It could however be shown that short-term interruptions (weekend, school holidays, and alike), introduced to alleviate aforementioned effects, do not affect the drug's beneficial effects in functional use (e.g., school). Such monitored medication breaks are often called "drug holidays" (D). They have become standard procedure in well-monitored treatment, predominantly including behavioral therapy.

Based on own experience in childhood and or hearsay, also a fraction of affected adults under stimulant medication expresses the desire to take drug holidays and "be themselves" from time to time. With the predominant fraction of medication being fast acting drugs in extended-release formulation and typical patients being not only highly compliant but also extremely informed and adherent, these so-called "drug holidays" are reported an accepted in therapeutically accompanied settings of adults by now.

However, while the overall positive effect of stimulant treatment on driving performance has been confirmed in a row of excellent on road- and/or simulation studies using integrated driving scores (IDS), so far there is no study available addressing the effect of drug holidays in adult drivers on driving performance. This represents a significant gap of evidence for both medical experts and affected.

The proposed study will address this gap by exploring parameters of driving simulation in relation to drug holidays in ADHD patients.

Inclusion criteria:

• adult drivers
• ADHD-diagnosed, established ADHD-treatment only with stimulants
• known history of drug holidays based on own decision,
• at impaired eyesight with more than +/- 5 diopter or astigmatism
• contact lenses are required (for eye tracking)

Exclusion criteria:

• sensibility to motion sickness (kinetosis, dizziness etc. in 5 min screening drive)
• non-stimulant-treatment
• inability to understand the study procedure for linguistic or cognitive reasons
• professional drivers (if working during the study period)
• for women: pregnancy

Results will be published in peer-reviewed journals. Anonymized raw data will be made available upon request.

starting after publication of study protcol and/or results

upon request by mail