A patient is brought with 6 month history of odd behaviour. There is a history of a family member having disappeared some years back. He seems to be talking to himself and sometimes muttering to himself loudly. The likely diagnosis is -
This patient is having:-


Disorganized behavior & thinking (talking to himself)
Disorganized speech (muttering to himself loudly)
Symptoms for 6 months


Diagnostic criteria for schizophrenia:- 2 or more of the following features (each present for more than 1 month), causing social or occupational dysfunction for more than 6 months:-

1)    Hallucinations; 2) Delusions; 3) Disorganized speech; 4) Disorganized or catatonic behavior; and 5) Negative symptoms.
Schizophrenia
Conversion disorder
Major depression
Delusion