Serious motor vehicle accidents
Dr. Larsson and his coinvestigators used registry data to follow 17,408 Swedish adults with ADHD for serious transport accidents involving a trip to the emergency room or death during 2006-2009. The risk was increased by an adjusted 1.47-fold in men with ADHD and by 1.45-fold in women with the disorder. However, in the within-individual analysis, men were 58% less likely to have a serious transport accident when they were on ADHD medication than when off medication. There was no statistically significant effect of ADHD medications on the risk in women with ADHD.
The investigators estimated that 41%-49% of transport accidents in men with ADHD could have been avoided had they been on drug therapy continuously throughout the follow-up period (JAMA Psychiatry. 2014 Mar;71[3]:319-25).
Similar results – that is, data showing that being on ADHD medication reduces the elevated risk of serious accidents – have been reported in four other independent studies conducted in Denmark, Germany, Hong Kong, and most recently in a U.S. analysis by Dr. Larsson and coinvestigators of more than 2.3 million patients with ADHD in a U.S. commercial health insurance claims database (JAMA Psychiatry. 2017 Jun 1;74[6]:597-603).
These findings collectively highlight the public health importance of diagnosing and treating ADHD.
But Dr. Larsson wanted his audience to take home another key lesson: “ADHD is a disorder that can be associated with serious outcomes, including suicide and accidents. It’s nevertheless important to remember that the absolute risks here are very low for any of these outcomes, so the majority of individuals with ADHD will never suffer from any of these outcomes. It’s important to keep that in mind.”
Dr. Larsson’s research is funded by the Swedish Research Council, the National Institute of Mental Health, FORTE, Horizon 2020, and Shire.