Depends. How big is your Canaanite idol or your multiple personalties disorder?
Seriously though...http://www.crivoice.org/demonsot.html - An interesting read on the translation. I've pasted the conclusion:
In summary, there is no Hebrew word that can be translated as "demons" to communicate what that word implies in English. There does lie behind the Old Testament conception a basic animistic and mythological world view with which the Israelites are in dialog. But they are using the terms and in dialog with such conceptions, not because they accept them or are dominated by them, but precisely to deny the validity of such mythological world views. The biblical writers use the terms not to accept what they represent but precisely to reject it. It is clear that there was a popular belief among Israelites in such things as ghosts and the mythological creatures of Canaanite religion. But the biblical tradition as it stands moves beyond such popular mythological conceptions to a vision of a Creator, a sovereign God who is in sole control of the world, and does not share that with anything or anyone. So again, there are no "demons" in the Old Testament, only idols that are rejected as "no-gods."
The New Testament accounts of 'demonic possession' resemble various forms of schizophrenia, epilepsy etc. Without modern medical advances and methods of diagnosis such as brain scans, people needed some way of explaining these episodes.