The whole story, showing "links" between cannabis and depression is a transparent beat-up of the kind exposed elsewhere on this blog so I won't analyse the whole thing.
But simply take the lie in the last paragraph which claims that cannabis smoking "leads to brain shrinkage", referring no doubt to the study discussed in the hyperlink above which in reality showed only a tenuous link to brain shrinkage and could equally have shown that unemployment is the cause (and it ignores a larger study which showed no shrinkage, both views backed up in a New Scientist report).
Again in the present case, the sample who mention cannabis to doctors came from atypical minorities, just like the 'brain shrinkage' and the 'cannabis causes violence' furphies spouted by NCIPC and published in The SMH. "Users were more likely to be male, young, unemployed or on a low income and indigenous", says the SMH story. So the study could equally have concluded that being a young unemployed Aboriginal is likely to lead to depression and dope smoking. That's not on NCPIC's agenda though.
There is another giveaway in the story, which: "...also revealed that mentioning cannabis use to a doctor was very rare". Jan Copeland is "disturbed" by this, another unscientific assertion about data that could equally show that very few of the 750,000 weekly users in Australia see it as a problem.
It's just like the junk studies that showed that 90% or so of cocaine users had smoked cannabis and concluded that pot led to coke use. But a simple re-examination of the stats demonstrated that only a small minority of regular pot smokers used coke, refuting the first conclusion. Be careful what you believe, dear reader, it's all smoke and mirrors (to use an apt analogy!)
For "balance" the story includes an ideological comment from the AMA's Dr Rod Pearce who essentially argues that cannabis causes harms under prohibition therefore we need more prohibition. THINK about it!
"The NCPIC mission is to reduce the use of cannabis in Australia by preventing uptake and harms associated with its use in the Australian community."