I'll be brief because we consider that to be more under provincial jurisdiction. The duty to warn has to overcome privacy issues, and so on.
Quebec passed “Anastasia's law”, Bill 9, after the Dawson shooting. With that law, medical professionals who notice a risk to public safety for a patient who owns a gun have to notify the Sûreté du Québec. This was recommended for other provinces to implement, but I don't think it falls under the purview of federal law. But we do support that, obviously.