A man hits his neighbour. Next day he feels that police is behind him and his brain is being controlled by radio waves by his neighbour. The probable diagnosis is:

C i.e. Delusion of persecution Delusions may occur in schizophrenia, depression, mania, bipolar disorder, organic disorders such as delirium, substance abuse and dementia but not in conversion disorderQ. Delusion of grandiosity (grandeur) or megalomania is characteristically seen in mania, organic delusional syndromes (such as neurosyphilis) , schizophrenia and paranoid disordersQ (i.e. schizoaffective mania and paranoid schizophreniaQ but not hypomania and cyclothymai = mild depression & hypomania). Nihilistic or depressive delusion (i.e. delusion of povey, guilt & nihlism) is seen in severe depression, and Cotards syndromeQ.