I was just quoting the expression used by the author of the article, but no, excessive devotion to religion is not necessarily psychosis. But it certainly can fall under the broader category of what is usually referred to as hyperreligiosity.
This is when the outward forms of the religious experience go beyond the bounds of true spirituality and become distorted into being the main focus of daily life to an exaggerated extent. Rather than it helping people to become more loving, more charitable, and being of more value to the rest of society, etc., it causes suspicion of everyone who doesn’t think the same, hate, angst and constant guilt. It destroys life rather than affirms it, because when in this mindset, it’s literally impossible to be religious and pious enough, to be perfect enough or to be"devoted" enough. It aleniates the sufferer from friends and family, and as we often see, from the mainstream of the group within which they are trying to be more religious and pious. They always seem to think they know what God is or was thinking more than anyone else does. Not psychotic, but there certainly is a potential for it.
It’s tough to fight this, because any attempt to help someone who is afflicted is seen as evil, or not religious. People have to eventually realize what is going on for themselves. But unfortunately, these days, a number of “movements” within the Catholic Church seem to encourage it.
To his credit, Pope Benedict, I think, is trying to gradually move back to the center with is frequent reminders that God is Love. He hints at it, anyway. At some point, these movements are going to rip the idea of Catholicism right out of the Church and split it apart if not checked somehow.
