Sunday, February 12, 2012

Marijuana nearly doubles risk of collisions

We hear a lot about the hazards of drunk driving, but here's something else to put on your radar: A study in the British Medical Journal found that marijuana nearly doubles the risk of vehicle collisions.

Researchers conducted a systematic review of nine studies on the subject of marijuana and driving accidents, which incorporated almost 50,000 participants.

Alcohol impairs drivers' speed and reaction time, while cannabis affects spatial location, said Mark Asbridge, associate professor in the Department of Community Health and Epidemiology at Dalhousie University in Halifax, Nova Scotia.

Among impaired drivers, fatally injured drivers, and motor vehicle crash victims, marijuana is the most prevalent illegal drug that has been detected, according to the U.S. National Institute on Drug Abuse.

Drivers who have recently smoked marijuana may follow cars too closely, and swerve in and out of lanes, Asbridge said.

People who are impaired by alcohol often recognize that they're impaired by alcohol, but "people under the influence of cannabis often deny feeling impaired in any way," Asbridge noted.

It's not unusual for young people to go to a party and give the "designated driver" responsibility to the person who uses marijuana, Asbridge said.

"There clearly is a lot of misconception about the extent to which cannabis impairs performance," he said. "People just don't believe it."

As with alcohol, cannabis has different effects on different people. People metabolize cannabis in different ways. Some inhale more than others.

The effects of cannabis tend to wear off within three to four hours, whereas alcohol can mess your thinking up longer. Depending on how much you drank, you may not be able to drive for up to 12 hours after you finish drinking.

If the driver is 35 or younger, there's a higher likelihood of marijuana consumption leading to collisions, previous research has found.

There's not enough information known about the effects of marijuana doses on collisions - in other words, what level of cannabis in a person's system correlates most with crashes.

And Asbridge's conclusions are based on observational studies, meaning there were no controlled conditions imposed to look at the effects of marijuana.

One problem in some of the existing research is that there was no measurement of cannabis within two to three hours of driving. Inactive metabolites of THC, a chemical found in marijuana, can be present in urine for weeks or even a month after usage; marijuana usage so long ago would not affect driving performance or collisions. So Asbridge's group looked only at studies where there was a recent measurement. They also looked at studies that looked at both drivers who used marijuana and those who did not to compare the collision rate.

To deter marijuana usage just before driving, there is roadside testing for cannabis in Australia, western Europe and the United States, Wayne Hall of the University of Queensland in Australia said in an accompanying editorial.

Hall called for further research to evaluating the impact of roadside drug testing on preventing driver deaths connected to vehicle accidents and cannabis use.

Post by: Elizabeth Landau - Health Writer/Producer
Filed under: Drug Safety

Thursday, February 9, 2012

Protecting our children from underage drinking

From Marilyn Belmonte, of Burlington Drug and Alcohol Task Force &

Recently, a parent attending one of my substance abuse prevention workshops in a nearby community asked my opinion on allowing her 17 year-old daughter to drink alcohol at home. The mother stated that she was very concerned about her daughter going off to college and becoming very intoxicated for the first time without any parent supervision.

The mother hoped that under her watchful eyes, her daughter would learn that alcohol consumption in large quantities can make her very sick. Perhaps she could even teach her daughter to drink responsibly. Then when her daughter is a college freshman, she will not participate in typical binge drinking activities.

The question is, does this practice work as a deterrent? Does allowing your teenager to drink freely at home deter them from getting drunk outside of the home?

It is impossible to say whether this parenting practice is beneficial for any individual adolescent but the science tells us that it will not work for the majority of teens. Numerous research studies show us that maintaining strict rules and consequences about underage drinking is most protective against teen alcohol use. Parents who use harm-reducing strategies such as allowing their high school teens to drink under their supervision, have a higher risk of those teens getting drunk outside of the home without parental permission than teens who are not allowed to drink at home.

Also, allowing your teen to experience alcohol in high school with parent supervision does not reduce alcohol use at college. Studies of college freshman show that heavy drinking occurs with a majority of students regardless of whether they started drinking alcohol in high school.

So the next question is, why bother trying to prevent high school drinking if it has little effect on college drinking?

It is well documented that underage drinking increases risk of adult alcohol disorders. In fact, the younger a person starts drinking alcohol, the greater that risk. Therefore, postponing the initiation of drinking as long as possible is a worthwhile effort for parents. The more years we can postpone the start of drinking, the more protected our children are from a lifelong alcohol addiction.

The last question is, how do parents postpone the onset of drinking?

Parental communication about their disapproval of underage drinking has been proven to help reduce the risk. Studies show that parents who are “soft” on teen drinking, are more likely to have teens who drink heavily.

Another factor that has been shown to decrease college freshman drinking is internal or “Intrinsic Motivation”. This is self-motivation driven by interest and enjoyment rather than external pressure, threat of punishment, or reward such as good grades, a trophy or money. The stress and pressure from external forces can actually drive heavy drinking. But one’s internal desire to achieve helps us to make healthier choices.

So encourage your teens to do their best at the activities they enjoy. Help them find areas of study that they are passionate about. Guide them in making goals for the future that excite them because postponing underage drinking is a worthwhile effort.