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.