Early cannabis use stifles academic success - study

Those who use cannabis before the age of 18 are less likely to succeed academically, a new study has found.

The collaborative study of more than 6000 New Zealanders and Australians found young people who used cannabis before age 18 were more likely to fail to complete high school, less likely to enter university and less likely to get a university degree.

Early users of cannabis were less likely to achieve academically even when other factors such as socio-economic status, previous educational achievement and other personal factors were taken into account.

The research was based on the combined findings of three studies, including the University of Otago's long-running Christchurch Health and Development Study, which has tracked over 900 people from childhood to age 30.

The other studies were the Victorian Adolescent Health Cohort Study and the Mater University of Queensland Study of Pregnancy.