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
A patient presents with one month history of abnormal hallucination and delusion. The patient lacks insight to his changed behaviour. Likely diagnosis is 
Select and explain. 
A. Paronia, B. Paronia, C. Psychosis, D. Schizophrenia
C: Psychosis
Answer: C: Psychosis 
Explanation: C i.e. Psychosis For a patient to meet the diagnostic criteria for schizophrenia, the symptoms must have been present for at least 6 monthsQ. With same symptoms if - Duration of episode of disturbance is > 1 day but < 1 month, then the diagnosis is Brief psychotic disorder. - Duration episode of disorder is > 1 month but < 6 months then the diagnosis is Schizophreniform (psychotic) disorder.