According to this Media Awareness Project article reprinting information from the Prairie Post, the Alberta Alcohol and Drug Abuse Commission (AADAC) with the Royal Canadian Mounted Police (RCMP) have compiled a fairly-detailed booklet to help parents talk to kids about drug usage.

Positives:

• It is fairly factually accurate in its portrayal of many drugs.
• It suggests parents create an open dialogue about drugs with their kids.

Negatives:

• Its portrayal of cannabis in particular is factually inaccurate, in particular:
  • "decreased motivation and interest, as well as difficulties with memory and concentration"
    • This has never been proven.
  • "chronic coughing and lung infections"
  • "cancer (As a result of the heavy use of pesticides and fertilizer in indoor grow-ops, the tar in cannabis smoke contains much higher amounts of cancer-producing agents than tar in tobacco smoke.)"
    • The prior two points are inaccurate; several studies have shown that cannabis users do not have any of the chronic lung issues that afflict tobacco smokers.
  • "psychological and physical dependence can occur among heavy or regular users."
    • Any study of cannabis has shown it has next to no physical dependence symptoms.
  • They also go to great lengths to state that cannabis grown today is much stronger than in the '60s. In fact, this increase in potency has would have an inverse effect on any issues that do in fact exist, due to less inhaled smoke.

Frankly, the way I see it, the best way to have a family discussion about drugs is around a Volcano.

The PDF is available here.