Just a point of interest. There's a journal article (that I don't have access to) that is titled,
Yoga therapy as an add-on treatment in the management of patients with schizophrenia--a randomized controlled trial
It seems that yoga therapy and "physical" therapy have significant effects on decreasing psychopathology in schizophrenic patients. The abstract also states that yoga therapy is significantly more efficacious than "physical" therapy. Of course - that's super interesting to me and I'd love to read more.
In contrast to these results, I'm aware of several (personal/non-scientific) examples of people having schizophrenic-like episodes that seem to have been INDUCED by yoga (kundalini specifically). There is some documentation of this - I believe the DSM-IV aludes to things that we might call "kundalini syndrome" under a "Religious or Spiritual Problem". Moreover, it does list, (and I'm lifting directly from wikipedia at this point - "Qi-gong Psychotic Reaction", described as "an acute, time-limited episode characterized by disassociative, paranoid or other psychotic or non-psychotic symptoms[...] Especially vulnerable are individuals who become overly involved in the practice." I think they call that - ZouHuoRuMo. (I'm going off point here...) . Its probably the equivalent of Kundalini syndrome in yoga.
So a while ago I read a book, titled, "Kundalini Yoga Meditation for Complex Psychiatric Disorders: Techniques Specific for Treating the Psychoses, Personality, and Pervasive Developmental Disorders" There's a picture of the cover at the top of this post. In the book, the author describes various kunalini yoga techniques for decreasing psychopathology in patients who undergo his treatment. Specific treatments needed to be done for specific types of disorders and for specific amounts of time. He outlines numerous case studies of his treatments and discusses how poorly clinical trials of anti-psychotics usually proceed since the side-effects of the treatments are typically very undesirable and the patients drop out. But...they're case studies. Then again, how can it hurt? Wait a second....maybe it could hurt...based on what I said in the last paragraph...hmmmm.....but people getting kundalini syndrome (that I know of) seem to get it from "casual" teachings - when not taken with serious respect from a teacher that knows what they're doing.....but then again...how do you know if your teacher knows what they're doing?....but then again.....
Anyway, I'd love to get my hands on that article and see how yoga can treat mental disorders in a randomized control trial setting. If anyone knows of extra studies etc. please pass them on!