I worked for Cigna for five years and saw all of this unfold on a daily basis. Sometimes it was blatant, and other times it was a bit more confusing. I completely agree that if a person has benefits and has not used them, then regardless of the level of care, especially if it is being recommended by an M.D., that person should be allowed to receive care for their issues. If they have no insurance, that's another complicated matter.
The one hang up, and I think this article pointed it out, is that when a person does not get the care needed, and they end up getting tossed around the system, getting "lower levels" of care, such as outpatient or intensive outpatient to save on cost, when the reality of it is that if they were simply allowed to receive a residential program from the beginning, maybe the years of hassle, other failed treatments, and expense could have been avoided. Unfortunately, once you've maxed your benefits for the calendar year, forget it, your done! And there is an abundance of elephant dung sized health care plans to see to it that you exhaust your benefits as fast as possible. In other words, if your benefits renew calendar year starting in January, and your actively seeking help for you mental health or substance abuse issues, you could conceivably max out by February, and spend the rest of the year without help or treatment, unless you keep paying out of pocket.
This issue could easily be a 900 volume tome, and I could ramble on at great length, but I guess from the insurance perspective, they only do what is necessary to keep a human being alive and functioning (feed themselves, dress themselves, bathe) at the bare minimum of expense, which I think is where the term "medical necessity" stems from. And why the insurance companies have the power to determine this over the M.D. treating the patient, I will never know. Mental health and substance abuse are not as easy a fix as mending a broken arm, or stitching up a wounded knee, they're much more long term, and progress can move very slowly. If I may be allowed to be a bit of a hippie about it, my hope is that if we the human species have any hope of progressing further, and sustaining life on this planet, the cost, no matter what ridiculous financial figures they produce, would ultimately become a true non-issue.
...bit of rant I know, sorry, just wanted to get that out and add it to the discussion. Thanks.