Paranoia can be cause by a lot of things, local environment, home & work environment. How can one overcome the distrust that causes paranoia? things that add to and attribute to paranoia are, watching people back stab each other, people lying, seeing unfair things at home and work. Suspicion and mistrust of people when their unfair actions affect you! In short one can develop paranoia from years of watching unfair bias behavior in others. Yet the definition of paranoia does not even hit on things that make people paranoid. Distrust of people and companies caused by their actions, is the root cause and is always over looked. The Psychiatric reason is way off base, this is my opinion.