The research – which tested 61 abstinent recreational users of illicit drugs in their mid-20s – has been published in Accident Analysis and Prevention as hundreds of thousands of young people begin to flock to music festivals and raves this summer.
With drug-related road accidents and deaths increasing worldwide, lead researcher and Swinburne Professor of Cognitive Neuroscience Con Stough, said he hoped the new evidence on driving impairment would help inform policy-makers and police, and especially those considering driving under the influence of drugs (DUID).
Professor Stough said the Swinburne, Vic Roads and Victoria Police research directly challenged a key Dutch study that found some aspects of driving were improved under the influence of methamphetamine and ecstasy.
“It’s interesting because our data contradicts studies in the Netherlands where they have put people in cars with a driving instructor. Our findings are very consistent with the emerging Victoria Police death and injury data that shows if you take these drugs you are more likely to end up in hospital with a serious injury, or even die,” he said.
For example, when the 61 volunteers were put in a driving simulator at Swinburne’s Centre for Human Psychopharmacology and given an ecstasy dose limited by ethical protocols, they showed a range of erratic and dangerous driving behaviour which made them ‘hard to read’ by surrounding drivers.
For ecstasy, “there was significantly higher exceeding of the speed limit, increased tail-gating, more skidding, significantly less signalling when changing lanes, and inappropriate braking. The main effect at night was they accelerated too fast,” Stough said.
“Under the limited methamphetamine doses, the drivers weren’t able to keep a safe distance, signalled more often but kept going in the same direction, and used their brakes when it was unsafe. Even a day later they often left their signals on after changing lanes,” he said.
These increased levels of erratic driving were exhibited during tests under limited amphetamine and ecstasy dosages ranging from half to 10 times lower than dosages shown to be typical of rave users.
“All the participants – while otherwise abstinent except for the tests – had been regular users of these drugs, so the effects were likely to be much less. For those contemplating trying these drugs for first time – with no tolerance, the consequences could be massively worse,” he said.
Joint Victoria Police and Swinburne data for December 2009 alone, showed that 20 drivers with methamphetamine and/or ecstasy in their system were seriously injured requiring hospitalisation.
Sixty per cent of the drivers were under 35 years, and 70 per cent were also using another drug.
Ninety-four per cent of the drivers with MA or MDMA were responsible for the collision in which they were injured, according to Professor Stough’s colleague, Victoria Police medical adviser and Swinburne Research Fellow, Dr Ed Ogden.
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