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
[{'content': 'All of the following are formal thought disorder EXCEPT: March 2013 (b, c, h) \nSelect and explain. \nA. Schizophrenia, B. Delusion, C. Loosening of association, D. Mania', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B i.e. Delusion Delusion is a disorder of thought content (NOT a formal thought disorder/disorder of thought process) Delusion Disorder of thought; False unshaken belief not amenable to reasoning Hallucination Disorder of perception; Perception in the absence of external stimuli; Not dependent of will of observer Illusion Misinterpretation of external stimuli', 'role': 'assistant'}]