zaterdag 19 april 2014

Automobilisten met ADHD rijvaardiger door medicatie?

Unmedicated ADHD Patients: Accidents Waiting to Happen?

Fran Lowry
January 30, 2014
Could patients diagnosed with attention-deficit/hyperactivity disorder (ADHD) who are prescribed
ADHD medications but who drive without them be a danger to themselves and others when they drive?
New research from the Karolinska Institutet in Stockholm, Sweden, suggests that this may be the case.
According to the results of a large registry study, ADHD is associated with an increased risk for 
serious transport accidents, a risk that might be reduced by ADHD medication, at least among men.
"Studies have shown that ADHD is associated with serious transport accidents, but it is unclear 
whether ADHD medication reduces this risk," senior author Henrik Larsson, PhD, told Medscape 
Medical News. "Our study demonstrates that the risk of transport accidents with adult men with 
ADHD decreases markedly if their condition is treated with ADHD medication."
The study was published online January 29 in JAMA Psychiatry.
Medication Reduced Risk
Several other studies have shown that adults with ADHD who drive without being on medication 
have less skill at the wheel compared with adults who do not have ADHD.
In a recent study presented at the 26th European College of Neuropsychopharmacology (ECNP) 
Congress and reported by Medscape Medical News, Esther Sobanski, MD, from the University of 
Heidelberg, in Mannheim, Germany, reported that the selective norepinephrine reuptake inhibitor 
atomoxetine, approved for treating ADHD, might improve adult driving skills.
Another study found that teenagers with ADHD became better drivers when they were trained on a 
driving simulator.
And in an earlier study, also reported in Medscape Medical News, researchers from the University of 
Virginia in Charlottesville showed that older adults with ADHD could be more prone to automobile 
accidents than their peers without the disorder.
Dr. Henrik Larsson
In the current study, the investigators studied 17,408 individuals with ADHD during a period of 4 
years, from 2006 to 2009, using various Swedish national registers.
They then analyzed the risk for transport accidents for those diagnosed with ADHD and how use of 
ADHD medication influenced this risk.
They found that, compared with individuals without ADHD, individuals who had ADHD had an 
increased risk for serious transport accidents. For men, the adjusted hazard ratio [AHR] was 1.47; 
(95% confidence interval [CI], 1.32 - 1.63), and for women, the AHR was 1.45 (95% CI, 1.24 - 1.71).
However, use of ADHD medication attenuated this risk.
Public Policy Implications?
In men, medication was associated with a 58% risk reduction (hazard ratio [HR], 0.42; 95% CI, 
0.23 - 0.75).
In women, however, there was no statistically significant association between medication use and
reduction in the risk for a transport accident.
From their analyses, the researchers concluded that 41% to 49% of the accidents in male patients with
ADHD could have been avoided if they had been receiving treatment during the follow-up period of the study.
"These results may be explained by ADHD medication having an effect on the core symptoms of 
ADHD, such as impulsiveness and distractibility, which in turn reduces the risk of getting trouble on 
the road," Dr. Larsson said.
"We could not establish a similar reduction in women's accident risk, and we need further data to be 
able to comment about the effect on women with statistical certainty," he added.
Dr. Larsson noted that the link between ADHD and serious traffic accidents does not, by itself, justify
withholding a driver's licence. Still, he added, the findings "do suggest that a large number of injuries 
and deaths due to traffic accidents associated with ADHD happened when patients were off their 
"Clinicians should consider informing their patients about the increased risk for transport accidents 
and the possible benefits of ADHD medication. This would not only provide opportunities to reduce 
morbidity and mortality for patients with ADHD but also contribute to the public's safety," he said.
Treatment Is Beneficial
Commenting on the findings for Medscape Medical News, Lenard Adler, MD, professor in the 
Departments of Psychiatry and Child and Adolescent Psychiatry at New York University Langone 
Medical Center, in New York City, called it "an important study because it follows up in a large, 
community-based registry findings that we have shown from small treatment studies."
Dr. Lenard Adler
Simulator studies have shown that adults with ADHD who are untreated have impairment in driving, 
and some of that impairment improves when they are treated, he said. "This study takes it out to the 
real world and looks at accidents, and then shows the percent of accidents that may have been reduced
by treatment."
Dr. Adler, who was not involved in this study, noted that prior research has shown that not all drivers 
with ADHD have impaired driving.
"The ADHD drivers fall into 2 groups. About half of them, from research done at Massachusetts 
General, are impaired, and about half actually drive okay, but in the group that's impaired, when they 
are put on a driving simulator, studies have shown that they have more speeding, false brakes, erratic 
driving," said Dr. Adler.
"They tend to accelerate into critical incidents on the simulator. For example, if you are driving along 
and you see a tree fall on the road and accelerate into that rather than brake, it obviously has serious 
consequences. If you give people with ADHD treatment, they drive better and have less of these 
errors on a driving simulator," he added.
The study by Dr. Larsson and colleagues highlights the importance of recognizing ADHD in adults, 
Dr. Adler said.
"If you don't know you have it, you can't treat it. If individuals have poor driving records, this may 
help clinicians identify some who have ADHD. This study clearly highlights the need and benefits 
of treatment and the importance of adhering to ADHD treatment," he said.
The study was supported by the Swedish Research Council, the Swedish Council for Working Life 
and Social Research, and the National Institute of Child Health and Human Development. 
Dr. Larsson reports no relevant financial relationships. Dr. Adler reports financial relationships 
with Eli Lilly, Shire Pharmaceuticals, Alcobra, and Theravance.
JAMA Psychiatry. Published online January 29, 2014. Abstract