To be honest with you, I'm not aware of any studies focused on what factors are creating this. I can tell you that isolation and poor or non-existent access to services deeply impact other populations, particularly in rural communities, and as far as the huge stigma goes, I cannot overemphasize the impact that has both with regard to governments providing services and in rural communities themselves.
One of the components of Roots of Hope I talked about is a training program within communities, plus a campaign. It allows people to talk and hear about mental health issues within the context of their own communities.