I liked PON but it did seem to fall under the "thanks I'm cured" or "happiness is a choice" school of personal development. It works for some people, maybe those who sometimes fall under a bad mood once in a while, but doesn't do much for real mental illness. It's like telling a lifelong alcoholic that drinking is a choice or an overweight person that eating is just a choice. How do you stay on that horse if you fall off it nearly every waking hour?
How to tell someone is trying to trash something. Unnecessary abbreviations. Its literally everywhere. The Power of Now is a transformational book and is extremely enlightening. Everyone should read it.