27 August 2002: The effects of cannabis and alcohol together have been shown to have greater effects than alcohol alone in research carried out in the UK by the RAC Foundation.

Drivers were plied with triple vodka and tonics and specially imported cannabis spliffs before going behind the wheel in a car simulator. The 20 participants were all males aged over 18 who were regular cannabis and alcohol users. They were recruited through people who were known to the project team and known to be regular cannabis users.

The report was prepared for the UK Department of Transport. The research was conducted to ascertain the effects of mixing relatively low doses of cannabis and alcohol on driving. The alcohol amounted to a blood alcohol concentration of 50mg of alcohol per 100ml of blood (80mg is the legal limit).

The National Institute of Drug Abuse (NIDA) supplied the 'grass' cigarettes whose strength was below what normally is sold on the high street. The vodka and tonics were administrated five minutes before smoking the cannabis.

Cannabis affected tasks that required more continuous attention whilst eye and hand co-ordination was impaired more with both alcohol and cannabis in the system than with either one on its own.

Robert Taylor, Managing Director, RAC Ireland, comments: "The research should convince the
Irish Government that there is a real need to launch anti-drink and drug driving campaigns nation wide, warning of these dangers. Even with relatively low doses of cannabis and alcohol, drivers are still at danger of veering across the road and causing a fatal accident.”