Was the woman in the Diagnose Me program exhibiting signs of demonic possession who improved with medical care, a lucky find of something treatable chemically, or do psychotic patients, in addition to having spirit possession as a primary cause, all have a biochemical abnormality, or possibly more than one, that is potentially treatable medically?

This is an insightful analysis. It is not universally the case that there is a clearly definable biochemical abnormality that can be determined scientifically, in tipping the balance to make spirits possessing a person more able to manipulate them in a dramatic fashion, bringing about the overt symptoms of demonic possession that become a danger to the patient and innocent bystanders at times as well. So there are possibilities to gain advantages from further research on the biochemistry of the central nervous system, to look for irregularities that might be amenable to therapeutic readjustment, to have them return to normal levels and configuration. These can be many and varied, and that works against the likelihood of this coming about any time soon in order to treat the huge number of individuals suffering from severe mental illness. That also does not argue against taking care of the spirit possession setting things in motion to disturb the mind. That is always important to take care of regardless of whether a medical treatment, as even with existing medication, can sometimes bring relief at the expense, perhaps, of numbing the mind too greatly. It is only a holding action, a kind of band-aid that does not solve the real problem, and this is why patients will usually not improve, and when they go off their medication their symptoms rebound. So it is always important to do a Spirit Removal for anyone with mental problems. Even the milder signs of mental abnormality are quite likely to be exacerbated if there are possessing spirits because they will work the levers to ramp up emotions that are negative, like anxiety, fear, and anger, and that worsens things and represents a severe impediment to healing.