If you're interested in a more general view of many of the issues impairing the current US Healthcare system, this was a great in-depth article by Time: http://time.com/198/bitter-pill-why-medical-bills-are-killin...

US FDA approval process is the highest in the world, but drug costs are also much higher here than other countries, which the above article also covers and may contribute.

Drug companies use, and even in some cases rely on the over-prescription of medication to fuel profits. This is a great in-depth piece by HuffPost (I was as surprised as you at the Huffpost part) on how Johnson&Johnson illegally marketed Risperdal to fuel profits: https://highline.huffingtonpost.com/miracleindustry/americas...

And there is evidence a scenario much similar to the above is currently occurring with Adderall: https://www.esquire.com/news-politics/a32858/drugging-of-the...

Hope you also find these interesting.