According to the fake thoughts and voices in my head my schizophrenia is a programmed disease, programmed by a highly advanced extraterrestrial species to be precise. They have two theories.
First one is that it’s a condition of the soul (consciousness) rather than the brain. According to that theory the extraterrestrials have learned to tap into and program the plane where souls exist. By doing that they can send targeted attacks down that plane in the form of “spirits” or “demons”, which are essentially pieces of code that are able to apply themselves to an individual’s soul, upon which that individual becomes “possessed”. The brain can then be affected via the soul<->brain interaction, or it can be active solely on the soul level.
The second one is based on the ancient astronauts theory, which in short claims that humans may have been in interaction with extraterrestrial species in prehistoric times. They say that the aliens may have modified the DNA of humans, and since the DNA contains all the information needed to build up a human being, they (being experts at genetic engineering) could have added the “code” for what we call schizophrenia.
The motives, according to the voices, could be either 1) control, 2) unknown to them, or 3) known to them but not allowed to tell me.