Delusional disorder

Delusional disorder is a mental illness characterized by delusions, fixed false beliefs that are not based on reality. People with delusional disorder often have trouble recognizing that their beliefs are not based in reality. The delusions can be bizarre or non-bizarre, meaning they can be either strange and unrealistic (e.g., believing that someone is spying on you), or could be based on persecutory, jealous, or somatic ideas (i.e., thoughts about the body). People with delusional disorder may become isolated and withdrawn due to their beliefs, and may experience difficulty functioning in social or occupational settings.