There is not one single cause to why as a country we find ourselves in this predicament. Yes, years of over-prescribing of opioids has taken its toll but substance misuse is also linked to poverty, trauma, family history, and many other elements that all come together to create this 'perfect storm' that we now find ourselves in. The solutions, like the problem, need to be equally as complex and recognize now only the provincial but regional differences that exist. The map below, taken from the national report published in 2017 on the opioid crisis (found here) adequately shows the provincial differences that exist at present in the magnitude of the problem. The regional differences in each province are less clear.
Unless you avoid the news altogether, you know that the opioid crisis is now in many regions of North America becoming extremely deadly with the addition of illicit (illegally) produced synthetic (man-made) opioids like fentanyl. This short video provides context to what fentanyl is and why it has now become such a significant concern.