25 and higher? Health committee hears age recommendation on pot

The province's chief of mental health and addictions is recommending a legal age limit of 25 years old for cannabis usage.

Younger marijuana users risk damage to their brain development, doctor says

Marijuana was one of the many topics covered in the province's health and wellness committee meeting Tuesday. (Matilde Campodonico/Associated Press)

The province's chief of mental health and addictions is recommending the legal age to consume cannabis be set at 25.

More people are smoking marijuana because of federal government discussions around legalization for 2018, Dr. Heather Keizer told the province's health and wellness committee on Tuesday.

And the younger pot smokers, she added, are putting their brain development in danger.

"I've seen a significant increase in the emergency room of adults and adolescents presenting with psychosis, secondary to marijuana use, who are using it now who wouldn't have used it three years ago," she said.

'Frontal lobes at risk'

"There is some good evidence to suggest that anybody who smokes cannabis under the age of 24 or 25 puts their frontal lobes at significant risk."

ADHD children struggle with frontal lobe function, she said "and we know that cannabis use can cause demyelination of the frontal lobes."

Dr. Heather Keizer says cannabis users under the age of 25 risk damaging the frontal lobes of the brain. (CBC)

Keizer described demyelination as taking an electrical cord — which represents a neurone — and scraping off the outer layer, or insulation, forcing the nerve to fire inappropriately.

This leads to a lack of development of the brain as well as dysfunctional frontal lobes, she said.

"These are children that are needing to develop their appropriate social interactions."

Disinterest in learning

She also said young marijuana users will develop a disinterest in learning that may damage their education.

"They don't necessarily follow through and finish their homework — they don't necessarily absorb that education like they might otherwise do.

"We would say abstinence is a great choice, but into the mid-20s is probably the place where you would initiate use."