Mental illness vs. demonic possession

When is mental illness a purely biological, biochemical effect, and when is there possible demonic involvement. This subject fascinates me, and to an extent, I explore the difficulty in discerning the difference in The Defilers.

Here's a link to a review about a new book that explores the subject.

Joan Naugle of the Post and Courier writes:

Throughout history, the people who founded hospitals, homes and assistance were all church-related. However, churches throughout time have not all been supportive. Many churches viewed mental illness as demonic possession, and some fundamentalists still believe so today.

Sigmund Freud called religion an obsessional neurosis. After his studies became well-known, religion was removed from hospitals. During the 1980s, there were few religious psychiatrists. However, the numbers have increased as research has placed more value on faith and mental health. All faiths, including Christians, Jews, Hindus, Buddhists and Muslims, strongly support the care of the mentally ill.

Part II of the book details research on religion and mental health. Studies show that when mental and physical health problems occur, most people turn to religion. Anxiety, depression, drug and alcohol abuse and anti-social behavior are also less frequent among religious people. Both longitudinal and cross-sectional studies show that religion helps patients deal with stress, trauma and other mental health problems.

About 80 percent of people with severe, persistent mental health disorders (schizophrenia, mania and psychosis) turn to religion and prayer to cope with their problems. Those who are religious have fewer re-hospitalizations and less health deterioration.