Well...it seems like you can imply this authors logic to any illness:

If you don't want heart problems, then do not eat greasy food and live an unhealthy life style.

...thus, there is no such things as "heart problems" just what you do to yourself to create such a problem.

... And if you don't do things that cause the problem, then the problem doesn't really exist, does it?

It's an subtle play on semantics I think.

I think this auther is asking a little too much of an individual: we cannot control all the things that happen to us, nor our emotional responses to them...if we could do that, then half of the problems in this world should have been solved!

Now granted, some mental illness's can be improved by taking a different perspective on them, but that is the cure for most alignments: taking a different out look on things, then using that to improve one's self, whether through medical help or other factors.

My opinion, of course