This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Psychiatry
Which one of the following disorders is related to sense of unreality? 
Select and explain. 
A. Depersonalization disorder, B. Derealization disorder, C. Delusion, D. Phobias
A: Depersonalization disorder
Answer: A: Depersonalization disorder 
Explanation: Ans. A. Depersonalization disorderDepersonalization:Depersonalization is a sense of unreality or strangeness concerning the self, manifested by feeling detached from and being an outside observer of one's mental processes or body.A patient who experiences depersonalization may describe feeling like things "I have stepped outside of myself and am watching myself doing things".Derealization:Derealization refers to feeling detached from one's environment so that the sense of the reality of the external world is lost.E.g, I feel as if everything is unreal and those around me are actors in a play or two dimensional cardboard figures.