The question of whether to permit the use of marijuana to help people with serious illnesses continues to divide opinions.

In Australia the premier of the state of New South Wales, Mike Baird, announced mid-September that the police would be given discretion not to charge terminally-ill adults who use marijuana for pain relief.

In the state of Victoria a bill has been introduced into parliament to facilitate clinical trials for the medical use of marijuana and there are similar initiatives in the state of Queensland.

Baird stressed that marijuana remained an "illegal and dangerous drug," according to agency reports on Sept. 17. He also said that: "Recreational use of drugs is illegal and will not be tolerated."

Medical opinion is still wary about the use of marijuana. A statement on the Web site of the Australian Medical Association acknowledges that certain substances in marijuana can be useful in treating pain. It stressed, however, that the risks associated with long-term use are not well understood.

The statement called for clinical trials. It also said that smoking or ingesting a crude plant product is a risky procedure.

Earlier in the year the president of the Australian Medical Association, Dr. Steve Hambleton, was interviewed on television following news that a family was administering liquid marijuana to their young daughter to help her cope with epilepsy.

He said that there are many different substances in marijuana and that the effects of all of them are not known. He would not administer it to any of his children, he added.

Canadian perspective

The Canadian Medical Association recently considered the use of medical marijuana and at their annual meeting passed a resolution on August 20 against the use of marijuana, especially when it involved smoking.

The outgoing president of the association, Dr. Louis Hugo Francescutti, explained that “there is evidence that smoking marijuana exposes people to many toxic chemicals in stronger concentrations than those found in tobacco.”

A more extensive statement by the Canadian Medical Association came in the form of a submission to the House of Commons standing committee on health, titled: “The Health Risks and Harms Associated with the Use of Marijuana.”

The submission, dated May 20, affirmed that: “marijuana usage poses serious health risks.”

This is particularly the case for teenagers, who are at greater risk because their brain is undergoing rapid, extensive development.

Marijuana contains more than 400 active chemicals, the submission explained. The concentration of these chemicals differs according to the plants, where they are grown and other factors. Contamination by pesticides is a related problem.

Moreover, the rate and quantity of the chemical absorbed by an individual will vary according to whether the drug is smoked, used in food, or inhaled. “This is challenging for research on the health effects of marijuana,” the submission noted.

Among the multiple side effects of marijuana is slowdown in reaction times, as well as an impairment of motor coordination and concentration. Its use is associated with an increased risk of motor vehicle crashes.

Mental health

Chronic use of marijuana brings with it an increased risk of psychosis, depression and anxiety, particularly among those who have a personal or family history of such problems, the submission explained.

Cognitive impairments such as a loss of memory, focus and the ability to think and make decisions are likely to be reversible a few weeks after discontinued use. This is not the case, however, for those who began using in early teen years, while the brain is still developing.

Further sobering information from the Canadian Medical Association was that chronic use is probably associated with bronchitis and emphysema and may also bring with it a risk for chronic lung disease and lung cancer, comparable to cigarette smoking.

The submission recommended a comprehensive education program to educate the public about the dangers of marijuana. This is particularly needed for young people, who are more likely to experiment with drugs.

Other medical experts have also expressed concern over the use of marijuana. A study carried out in the United States among casual marijuana smokers found evidence of changes in the brain, according to an April 15 report by the Associated Press.

The young adults who volunteered for the study were not dependent on the drug compared to a control group showed differences in two brain areas associated with emotion and motivation.

"What we think we are seeing here is a very early indication of what becomes a problem later on with prolonged use," things like lack of focus and impaired judgment, said Dr. Hans Breiter, a study author.

While growing numbers of people are in favor of using marijuana for medical purposes the evidence clearly shows that there are many serious issues to be taken into account before giving approval.