This story got an resounding "no duh" from me... Most (maybe all) of the people I know that still indulge on a regular basis are definitely loopy in the clinical sense. I know it's a chicken or the egg scenario --Do they still smoke pot in their 30's because it calms their mental illness or did the pot help induce the mental illness?
"...THE use of cannabis, particularly among young people, substantially increases the risk of mental illness and worsens existing mental health conditions, a major report has found.
Where There's Smoke: Cannabis and Mental Health, by the Mental Health Council of Australia, said the drug's dangers were underestimated and called for an education campaign.
The research found cannabis use could trigger psychosis in some people and could induce schizophrenia in those with family histories of mental illness.
There was a link between early and regular cannabis use and later depression, but little evidence to suggest people turned to cannabis because of existing mental health conditions.
The council's chief executive, John Mendoza, said there was now proof smoking cannabis had serious mental health risks.
"You increase that risk further if you have a family history of mental illness," Mr Mendoza said.
"You increase the risk again a notch further if you begin using at a young age, when brain development is at crucial stages.
"And you increase the risk a further step if your use is regular and prolonged, and if you use the substance in a way that increases its potency through the use of bongs." (source)
Sorry to any of the tokers I know...don't shoot the messenger. ;)