Garee, the word "Possessed", or the way in which you are asking, “demon possession” is frequently used in English translations of the New Testament, most notably in the Synoptic Gospels, to render the meaning of the term daimonizomai.
The Scriptures suggest that the terms “with an unclean spirit” (en pneumati akathartō) and “having a demon” (echōn daimonian) are viewed as similar in meaning both to each other and to daimonizomai.
These terms seem to indicate the presence of demons or unclean spirits, who are exerting a degree of regular or intermittent and pernicious influence in a person’s life so that the person has lost control of their body and thoughts.
That is different that "OPRESSION".
As has been stated, a born again Christian believer can not be DEMON POSSESSED! That is an impossiblity.
ALL people, either lost or saved can be "OPREESSED" by Satan and in fact ALL of us are or will be.