New statistics from ACT Health show 50 children under 18 were treated at Canberra and Calvary hospitals after consuming illegal drugs like marijuana, heroin, cocaine ecstasy and vast quantities of liquor last year. Of the 50 children, three were under 13.

University of NSW alcohol and drug expert Richard Mattick said a 14-year-old needed to drink most of a 700-millilitre bottle of spirits quickly to end up in hospital.

''Alcohol poisoning or toxicity will occur only with very high levels of alcohol consumption- where the child downs the best part of a bottle of Jim Beam,'' Professor Mattick said.

''The danger is alcohol poisoning can actually cause death - but most people don't drink that much because they pass out after eight to 12 drinks. After six drinks they are intoxicated at age 12, or asleep or vomiting. So to drink enough to have alcohol toxicity or poisoning is to ingest a lot very quickly.''

Professor Mattick said children who regularly drank alcohol had different brain function to those who did not.

''There is increasing evidence that regular exposure to alcohol in young people from early to mid teen years is associated with changes in brain function, in efficiency, in attention.''

He said children who started drinking or using drugs under the age of 18 were at greater risk of becoming alcoholics or escalating their drug use.

''Alcohol poisoning, it's increasing somewhat … young people are more willing to drink spirits or shots, chasing a beer with two double vodkas, those kind of behaviours are relatively new to the current generation.''

The former director of the National Drug and Alcohol Research Centre has called for the drinking age to be raised to 21.

A spokeswoman from ACT Health said some of the children could have overdosed accidentally.