The Federal Task Force provided the following summary of the health effects of cannabis in the Discussion Paper ‘Toward the Legalization, Regulation and Restriction of Access to Marijuana’:

“Cannabis carries both health risks and potential therapeutic benefits. Most research on cannabis over the past five decades has focused on harms, with much less attention placed on potential therapeutic benefits. The illegal status of cannabis has made it difficult to draw a complete picture of the harms of its use compared to those associated with alcohol or tobacco use, or other psychoactive substances. The following summary is based on the current available evidence.

 

Risk Factors

In general, health risks associated with cannabis use can be acute (i.e., immediate and short-lived) or chronic (i.e., delayed and longer-lasting). However, the risks may increase significantly depending on a number of factors, including:

  • age at which use begins;
  • frequency of use;
  • duration of use;
  • amount used and potency of the product;
  • a user’s actions while intoxicated, such as driving or consuming other substances or medications; and
  • a user’s health status and medical, personal, and family health history.

 

Therapeutic Benefits

With respect to claims of cannabis’s therapeutic benefits, aside from clinical studies with cannabis-derived products that have received market authorization in Canada, only a limited amount of credible clinical evidence exists. Some clinical studies suggest that strains containing mainly THC have potential therapeutic benefits for some medical conditions, including:

  • severe nausea and vomiting associated with chemotherapy;
  • poor appetite and significant weight loss as a result of serious long-term or terminal disease (e.g., cancer, HIV/AIDS);
  • certain types of severe chronic pain (e.g., neuropathic);
  • symptoms associated with inflammatory bowel disease;
  • insomnia and anxiety/depression associated with serious long-term disease;
  • muscle spasms associated with multiple sclerosis; and
  • symptoms encountered in palliative care settings.

Emerging evidence also suggests that cannabis strains containing mainly CBD may be useful in treating treatment-resistant epilepsy in children and adults.”