A 60 yrs old male suffering from auditory hallucination says that people staying upwards are talking about him and conspiring against him. He staed getting this feeling since one month. He dropped a police complaint against them but the allegations were proved to be wrong. The diagnosis is:

This patient with auditory hallucinations and delusions of persecution is mostly likely having schizophrenia. Patients with schizophrenia may present with positive symptoms (such as conceptual disorganization, delusions, or hallucinations) or negative symptoms (loss of function, anhedonia, decreased emotional expression, impaired concentration, and diminished social engagement) and must have at least two of these for a 1-month period and continuous signs for at least 6 months to meet formal diagnostic criteria. Ref: Meltzer H.Y., Bobo W.V., Heckers S.H., Fatemi H.S. (2008). Chapter 16. Schizophrenia. In M.H. Ebe, P.T. Loosen, B. Nurcombe, J.F. Leckman (Eds), CURRENT Diagnosis & Treatment: Psychiatry, 2e.