A clinical psychologist​ from the the University of British Columbia says he doesn't expect huge changes on university campuses when marijuana is legalized.

Zachary Walsh, who is working with the Canadian Institutes of Health Research, is examining the consequences of the legalization of marijuana on campus.

"I don't think it's been a barrier to using and I think that was kind of the point behind legalization is the people are using anyways, so how can we reduce the harms associated with that," Walsh told CBC New Brunswick News.

Walsh said once marijuana is legal, it will be less harmful and students will be less likely to be accessing it from the illegal market.

"If they do that they're not going to be as readily exposed to other potentially more dangerous substances."

Dr. Zachary Walsh, a clinical psychologist​ with the University of British Columbia says he doesn't expect to see huge changes on university campuses when marijuana is legalized. (CBC)

Walsh said he also believes students will be more open to discuss their marijuana use with health-care providers.

"I think it's going to have a positive effect on Canadian campuses where people are using cannabis anyhow," he said.

The psychologist said many of the problems that take place on campuses are related to excessive alcohol use and his research shows the use of cannabis may help to reduce binge drinking.

"People may choose to use cannabis as a substitute, but that's less likely to happen if the only access that people have on campus is to alcohol."

Walsh said many campuses have bars, or there are bars nearby. He said if there is no access to cannabis there is nothing to slow the use of alcohol.

"So I say put it on an even playing field with alcohol … and that's going to really allow us to see if it's going to reduce the harms associated with alcohol."

Walsh disagrees with campuses banning the use of marijuana outright and says they should be allowing what is going to be law to continue.

"If you provide people with a safe place for smoking cannabis then they won't offend those who don't want to be in contact with it. And they won't risk getting in trouble for pursuing their rights."

The clinical psychologist​ says there is a big difference between cannabis use and legalization. Walsh agrees there are downsides to its use.

"It can interfere with short-term memory and, if people are smoking it, it can be irritating to their respiratory​ system. So those are negative consequences, but I don't expect those consequences to increase with legalization."