The effect of ADHD symptoms in traffic accidents

Abstract

Attention deficit/hyperactivity disorder (ADHD) is one of the most common psychiatric disorders among children and adolescents. Adult ADHD is often underestimated and untreated, but may influence drivers’ behaviour in traffic. The objective of the present study is to clarify how symptoms of ADHD are associated with different types of traffic accidents. A subsample of the subjects of Estonian Psychobiological Traffic Behaviour Study was recruited at driving schools in 2014 (n=1288, mean age 23.9 (SD=9.9) years). The subjects completed web-based questionnaires including social-demographical data (gender, age, education) and the WHO Adult ADHD Self-Report Scale (ASRS) (Kessler et al., 2007) when they entered study. Data of traffic accidents from 2014 to spring 2015 were obtained from the traffic insurance fund. The Ethics Committee at the University of Tartu approved this study. This research was supported by the Health promotion research programme (TerVE) funded by the European Regional Development Fund and implemented by the Estonian Research Council. The subjects were categorized according traffic accidents respectively: 1) responsible for the traffic accident (n=26, 2.02%), 2) victim in the traffic accident (n=25, 1.94%), and 3) participating in traffic accident (n=47, 3.65%) – subjects who were responsible for the traffic accident and/or victim in the traffic accident. Males participated more often than females in all traffic accidents (p=0.0002), and in accidents as the victim (p<0.0001). Subjects with traffic accidents had significantly higher scores in the ADHD screen, inattention, hyperactivity and impulsivity, and ADHD total scales irrespective of category (Figure). Subjects with university education reported significantly higher ADHD scores in all subscales (p≤0.01), especially in attention (p=0.0003). All the associations between traffic accidents and ADHD measures remained significant when accounting for education. Subjects who reported more ADHD-related symptoms participated more likely in traffic accidents, both being responsible for and victim in accidents. Hence ADHD symptoms should be acknowledged in the curricula in driving schools for preventing traffic accidents.