There are a lot of different factors that have the potential to cause psychiatric disorders: life circumstances and tragedy, diet, lack of sunshine and Vitamin D, genetic predispositions, trauma, spiritual problems—the list goes on. As a Catholic Christian I certainly see evil forces as contributors. But that doesn’t mean we shouldn’t use every weapon in the gun cabinet to fight it, and along with spiritual weapons we should use medical research as well. For even if there is a situational contributing factor, sometimes we can’t even reach emotionally ill people verbally to help them with their problems. Sometimes medications can lift them up to the point that they can accept help. Drugs do have their uses.
bkmk
I wasn’t saying that drugs weren’t an effective intervention but rather than an effective intervention doesn’t mean you have identified the root cause of the disorder (e.g., autism - the most effective interventions are those based on behavior analysis but we still have no clear idea on the cause/s of autism).
As for faith, I too am Catholic. Our church teaches behavior resulting from psychiatric disorders can be something different than corruption by sin. That is, if the psychiatric illness precludes the person from understanding the sinfulness of the act and fully consenting to the act, then culpability is greatly diminished (there is a decent discussion here - https://www.osv.com/TheChurch/HumanDignityandSexuality/Article/TabId/658/ArtMID/13696/ArticleID/8366/Responsibility-for-sin.aspx).
Now, I may have misunderstood what you were saying. So if you were simply saying that we should include prayer and spiritual exercises in the treatment of psychiatric disorders, as long as they don’t preclude or interfere with other effective procedures (God has given us the intellect and skills to identify ways, beyond prayer, to help our fellow man and I would argue that they are therefore, in some ways, spiritual gifts from God), I agree wholeheartedly.