CSC's Addiction Research Centre has developed some impressive protocols for doing culture-based treatment with aboriginals. Those are materials that are available. I'm not sure how well disseminated they are, or how well delivered they are across the country, but there are these models.
Rather than thinking of this as an overwhelming problem, it's important to start to segment it. An effective strategy that has an aboriginal focus takes care of a fifth of the problem, because 20% of people in prisons are aboriginal. The more you can have targeted strategies that address that population and others, the more effective your overall approach will be.
You could also develop strategies oriented to particular forms of addiction and mental health, targeting programs to those populations. It's through developing targeted approaches that we can have more success in our interventions.