@hawkeye10,
The vast majority of 'sexual' and drinking related problems is because the white man did horrible things to them. Sticking them in reservations with no jobs, money or hope. And then there were the schools... The legacy from racist policies has caused generations of pain and suffering. Children were ripped from their parents arms, isolated and saw white man raping and pillaging there communities, "normal" behavior was unknown. We all learn from our parents and community. When parents and children are told they are less than human and treated thusly, how are they supposed to know what is normal? When the people that treated them like animals were backed by ignorant government officials and policies, how did this teach them anything better? Generations of people are scarred and it will take several more before they can heal fully.
However, the tide is turning and there are many well educated Natives now leading and helping their communities.