You are confusing the actions of a practitioner and a “patient”. A shaman is a practitioner. The one “invaded” by evil spirits is the patient.

If someone said “The voice in my head told me to kill my parents, and I always do what the voice in my head tells me to do.” then yes, I would say that individual is in serious need of immediate medical attention.

If someone said “The voice in my head told me to jump off a bridge.”, again – medical attention.

If someone said “I moved with a days notice to California from Oregon because 'some sort of entity attached to me, or my aura/field and it keeps following me' ”, hmm… medical attention.