This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Symptoms & Signs , Subject name: Psychiatry
Delusion is the disorder of: 
Select and explain. 
A. Thought, B. Perception, C. Always organic, D. Always psychiatric
A: Thought
Answer: A: Thought 
Explanation: Ans. a (Thought)DELUSION is false belief in something that is not true.Types of delusions are:1. Primary delusions (autochthonous delusions): Arise denovo, cannot be explained on the basis of other experiences or perceptions. They are characteristic of early schizophrenia.2. Secondary delusions: Commonest delusions seen in clinical practice and many psychological disorders.Commonly seen delusions in schizophrenia are:1. Delusion of grandeur2. Delusion of persecution3. Delusion of reference4. Delusion of control.