AHD: "1. A psychotic disorder characterized by delusions of persecution with or without grandeur, often strenuously defended with apparent logic and reason. 2. Extreme, irrational distrust of others." < Gk para- 'beside' + noos 'mind'. Besides paranoia, there's also narapoia :- "That uneasy feeling that you are unintentionally following someone." And, finally metanoia :- Having gone beyond one's mind.