Greater Risk of Mental Illness from Smoking Marijuana

15 Oct 2000

The AMA has warned that people who regularly smoke marijuana are at greater risk of triggering a psychosis such as schizophrenia.

A new AMA harm minimisation brochure Cannabis and Your Health warns that cannabis can trigger further bouts of illness or destabilise the treatment of illness.

AMA Public Health spokesman, Dr Bill Pring, said there was strong and increasing evidence to show that use of cannabis by people who had experienced a nervous breakdown was unwise and should be discouraged.

"Some people may be more vulnerable to developing psychosis than others, but we don't know how to pick who is vulnerable at this stage," Dr Pring said.

"Sometimes the psychosis that occurs when it's associated with cannabis use does not go away, despite treatment," he said.

Dr Pring said the Australian Institute of Health and Welfare's Statistics on Drug Use in Australia 1998, published in March 2000, described 44% of young people aged between 14 and 19 years as "life-time users" of marijuana.

"In 1995, less than 25% of young women in this age group were life-time users. In three years that figure has jumped to almost 45%. Males in this age group have stayed at the same high rate of 44%," Dr Pring said.

He said the report also described 39% of all Australians aged over 14 years as life-time users.

"If you smoke marijuana regularly it is also likely to affect your concentration and your capacity to recognise important information," Dr Pring said.

"We are trying to raise awareness of the health risks associated with cannabis use, particularly among young people who may not have the necessary information to make informed decisions," he said.

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