Devout vs. mentally unstable

Any psychologists out there? What are the distinguishing characteristics/actions between someone who is extremely devout (say, pratically sinless, prays constantly) and someone who has a disorder (for example, obsessive compulsive)?

Dear friend,

It seems to me that a person who is compulsively pushing prayers, reciting them by rote, avoiding evil due to scrupulosity, would eventually show the cracks in their spiritual wall. Nobody can live a truly spiritual life unless they are grafted into the Vine, who is Christ Jesus. It is through Him, with Him, and in Him, that we are able to produce the fruit of holiness. There is no other way.

A person who lives a devout life through sanctifying grace and a true relationship with Jesus, will eventually be recognized by his virtue and good works — especially if it is manifested in a severe trial. Patience, peace and joy in suffering the evils of life are not easily born by someone who is simply going through the motions, but not authentic in spirit.

I hope this sheds a little light for you.