by: David Rabiner, PhD
For many parents, the day their teenager begins driving introduces a host of new worries and concerns. When that teen has ADHD, however, these concerns are often amplified as multiple studies have documented that adolescents with ADHD have more accidents and engage in more risky driving behavior than other teens.
One possible explanation for these findings are the core ADHD symptoms of inattention and impulsivity, or perhaps the oppositional behavior that often accompanies AHD, contibutes to poorer driving outcomes. It is reasonable to hypothesize that being inattentive and easily distracted would contribute to driving accidents and that impulsive decisions, e.g., cutting across lanes quickly to avoid missing an exit, could lead to accidents. Or, high levels of oppositionality may lead to a greater disregard for traffic rules/regulations.
A less obvious factor that may contribute to poor driving outcomes for teens with ADHD would be a tendency to overestimate their driving competence. Overestimating one’s driving ability could lead to teens taking greater risks because they believe they are ‘good’ drivers and can afford to take risks. They may also learn less from driving mistakes if they believe that because they are such good drivers, they don’t need to worry about a similar mistake happening again.
Multiple studies of children with ADHD indicate that they tend to overestimate their competence in different domains relative to ratings made by those who know them. There is also some research documenting this tendency among teens with ADHD, including one study suggesting that the relationship between ADHD symptoms and risky driving outcomes is explained by the tendency of teens with ADHD to overestimate their behavioral competence. In related work, young adults with ADHD rated their driving skills similarly to other adults, even though their objective performance in a driving simulator as well as their driving record was significantly worse.
A study published online recently in the Journal of Attention Disorders took a closer look at the tendency of teens with ADHD to overestimate their driving skills and whether this may contribute to poorer driving outcomes [Fabiano et al., (2015). Positive bias in teenage drivers with ADHD within a simulated driving task.Journal of Attention Disorders, doi: 10.1177/108705471616186].
Participants were 172 16 to 18 year old youth diagnosed with ADHD (72% male); approximately 70% were receiving stimulant medication. As part of a larger study examining driving interventions for teens with ADHD, all youth participated in a driving simulator exercise that lasted 20 minutes. The simulator consisted of a front-seat real vehicle passenger cabin, an actual steering wheel, and regular floor pedals. The virtual simulation driving environment – which was presented on a computer screen – was modeled after actual roads from local neighborhoods. Youth were instructed to drive through the ‘neighborhood’ as they typically would; as they negotiated the simulated environment, the simulator continually monitored their speed, whether complete stops were made at stop signs, and how they reacted to roadway obstacles and hazards that appeared.
ADHD Symptoms – Each teen and his/her parents rated ADHD symptoms using a standardized rating scale called the Disruptive Behavior Scale.
Driving Behavior – Teens’ driving in the simulator was rated by teens and by an adult observer. This 17-item measure inquired about specific negative driving behaviors during the simulated driving task, e.g., speeding, crossing into the wrong lane, failing to stop fully at stop signs, etc.
Overall driving performance ratings – In addition to rating specific driving behaviors, teens and observers provided an overall rating of the quality of the teen’s driving.
Simulator behavior composite – The number of instances of 5 specific driving outcomes was calculated for each driver. These included the number of deer hit when animals ‘ran’ into the roadway unexpectedly, the number of traffic cones hit in construction zones, how often the car deviated from the correct lane, instances of speeding, and rolling through stop signs. This composite store provided an ‘objective’ indicator of negative driving behavior.
Ratings of ADHD and oppositional symptoms – Teens reported significantly less severe ADHD symptoms than parents. The magnitude of this difference was large and particularly large for ratings of inattentive symptoms. Teens also reported lower levels of oppositional. This replicates findings that have consistently been reported in younger children.
Ratings of driving behavior – Teens rated their driving behavior more favorably than observers, both for specific negative driving behaviors and for overall driving quality. This reflects a ‘positive bias’ in that teens themselves as better drivers than adults who observed them. Teens’ bias was greater for the overall performance rating than for ratings of specific driving behaviors.
Relationship between positive bias and risky driving – In a final analysis, the researchers examined the prediction of the cumulative number of dangerous driving behaviors recorded in the simulated driving task. Predictors were parents’ rating of oppositional behavior, gender, medication status, and how positively biased teens were in rating their overall driving quality. The only significant predictor of negative driving was the size of this positive bias; specifically, the more biased the rating the higher the rate of negative driving behavior in the simulator.
Summary and implications
Results from this study indicate that teens with ADHD underestimate their behavioral symptoms relative to parents and overestimate their driving competence relative to adult observers. The positive bias for driving performance was greater for the overall driving rating than for ratings of specific behaviors, but was statistically significant in both instances.
These findings have important implications because teens who overestimate their driving ability may take more risks while driving and learn less from their mistakes. It was noteworthy that the size of teens positive driving bias was the only significant predictor of their actual negative driving during the simulation task.
Based on these findings, the authors highlight suggest that clinicians working with teens diagnosed with ADHD should provide precise driving recommendations and monitoring strategies to families. Additionally, they caution against relying on teens’ self-report of their driving and suggest that parents consider the use of objective indicators of driving performance such as on-board engine performance monitors and/or in-vehicle video recorders. Such measures are not likely to be well-accepted by many teens, however, and may engender conflicts that that become another source of difficulty. Certainly, this is an area where working with a professional experienced in helping families negotiate these issues could be helpful.
There are limitations to this study that are important to note. The most significant is the absence of a non-ADHD comparison group. It would not be surprising if adolescents without ADHD also overestimated their driving competence and this study provides no information on whether the bias displayed by teens with ADHD is larger than for other teens. This would be an important issue to examine in subsequent research. It would also be interesting to know how the driving performance compared for teens who were and were not being treated with medication; medication status did not emerge as a significant predictor of negative driving performance but it was not clear whether teens were on medication at the time of the driving test.
Finally, although a particularly interesting finding was that teens’ positive bias, and not their level of oppositional behavior, predicted negative driving in the simulator, it is not clear why parent ratings of ADHD symptoms were not included in this analysis. Perhaps ratings of core ADHD symptoms would have emerged as more important. Given that this is a study of youth with ADHD, it is a perplexing omission.
In summary, results from this interesting study highlight that teens with ADHD are likely to overestimate their driving competence and this may be an important factor contributing to negative driving outcomes, perhaps even more important than their behavioral symptoms. This suggests that efforts to engage teens in realistic discussions about their driving skills, and working with them to develop accurate appraisals of their competence, would be useful for parents and clinicians to pursue.
David Rabiner, Ph.D.
Dept. of Psychology & Neuroscience
Durham, NC 27708
(c) 2016 David Rabiner, Ph.D.
This article was originally published in Attention Research Update, an online newsletter written by Dr. David Rabiner of Duke University that helps parents, professionals, and educators keep up with new research on ADHD and related areas. You can sign up for a complementary subscription at www.helpforadd.com
Reprinted with permission. All rights reserved.