Insurance Coverage of Treatment

I recently heard a story of a 19 year old teen who is struggling through addiction because his family doesn't have enough money for treatment, and his insurance company claimed "he wasn't severe enough for in-patient rehab." From the story I received, he was actually in dire need of help at such a crucial time in his life. So, this led me to the question of what role insurance plays in treatment. I discovered a few things on some treatment cites including the need for a facility to prove everyday that the patient still needs care and that chances of coverage become slimmer if the person is not responding. These strict regulations are kind of scary when concerning someone's health and well-being.
I also came across the Paul Wellstone and Pete Domenici Mental Health Parity and Addiction Equity Act of 2008 which "forces insurers to pay more for substance abuse and mental health-related problems." This will help people that have an insurance policy with benefits regarding treatments. But addiction and especially mental illness is very difficult to diagnose as a disease which makes it less likely to be insured on treatments for them. At the same time, many people don't predict a need for rehab/treatment when searching for an insurance policy, so what could guarantee that the people in need are the ones with these benefits. At least this Act is making progress towards helping those suffering from addiction or mental illness financially, but more can be done.