There is no overconsumption of legal marijuana among adolescents in Rhode Island, a new study shows.

Study researcher Dr. Esther Choo of Brown University said in a statement that she did not find increases in marijuana use among Rhode Island's youth after medical marijuana was legalized in the state.

"However, additional research may follow future trends as medical marijuana in Rhode Island and other states becomes more widely used," the doctor said.

The study surveyed results from 32,570 middle school and high school students in Rhode Island and Massachusetts, which has not legalized medical marijuana. Survey results were taken as part of the Youth Risk Behavioral Surveillance System, completed between 1997 and 2009.

The study showed difference in illegal marijuana use among youths between the Rhode Island and Massachusetts in any year within the aforementioned period.

Choo presented the study's findings on Wednesday at the American Public Health Association meeting in Washington, D.C.

A number of surveys have been conducted to determine the society's insight on the legalization of marijuana. In 2009 O'Leary Report surveyed 3,937 respondents and found 52 per cent in favor of legalization. An earlier ABC News/Washington Post poll found 46 per cent supportive of the cannabis. In California, a Field Poll found 56 per cent to be pro-legalization.

In 2008, an Australian study reported long-term, heavy cannabis use causes brain damage that is equivalent to mild-traumatic brain injury or premature ageing. The research was published in the journal Archives of General Psychiatry.

It is illegal to use, possess, grow or sell cannabis in Australia, but penalties vary across states or territories. In Queensland, under the Police Powers and Responsibilities Act 2000, a person who admits to carrying 50 grams or less (and not guilty of any other offence) must be offered a drug diversion program.