A team of Canadian researchers has found that teenagers, who begin smoking pot as early as 15 or younger, may suffer long-term cognitive impairment, memory loss, physical illnesses and respiratory diseases.
The findings, published in the journal Health, shows that young users, who smoked pot, reported the most impact to their physical and mental health and those who did not smoke until age 21, are unlikely to develop a lifelong habit, or barely smoke pot at all.
"The task force outlines these benefits to take marijuana out of criminal hands, to tax it, to make sure that product quality is preserved," said lead author Dr James McIntosh.
"We need to start collecting data on it to see what the effects are on people of all ages," McIntosh added.
Researchers from Concordia University in Montreal, Canada, looked at data from the 2013 Canadian Tobacco, Alcohol and Drugs Survey, and two others, to determine the effects of cannabis use on self-reported physical and mental health.
The results indicated, when use began below age 15, the drug was found to cause cognitive impairment, memory loss, diminished IQ, limited educational success and likelihood for developing mental illness.
Those who began smoking marijuana at age 17 or younger had an average 62.5 percent lower chance of receiving a high school degree.
The students who smoke high amounts of cannabis have lower grades and perform worse at school.
Physically, early users also suffered higher rates of respiratory diseases and certain cancers and may also increase the likelihood of long-term habitual use.
The researchers suggested that educational programs, counseling services and a distribution system could help minimise use by young people.