A pneumasomatic disease is a physical condition which arises in the spirit. Similarly, it is probable that a psychosomatic disease is a mind/body disease which also arises in the spirit. In brief, penumatherapy is a spiritual form of self-hypnosis. By the way, Dr. James Braid, who coined "hypnosis" in 1843 to replace mesmerism and yogism, did not like the term. Later, without success, he tried to introduce "monoideism" --the ability to keep one's mind on one idea--a good description of the trance phenomenon.
Even many modern "hypnotists", in order to get away from the false perception many people have regarding hypnosis will call what they do, "mentalism" and themselves, "mentalists".
It is probable that most conditions are a complex combination involving pneuma, psyche and soma factors.
Pneumatherapy, then, is a unique kind of self-hypnosis, not unlike neuro linguistic programming. Check out the following site for a good definition of what pneumatherapy is all about:
You will note that this is not the regular stage variety of hypnosis in which "subjects" appear to be manipulated by a "master".