The Man Behind the Royal Massacre.

Delusional disorder is a relatively uncommon psychiatric condition in which patients present with non-bizarre delusions, but with no accompanying prominent perceptual disturbances, thought disorder or significant and sustained mood symptoms. Apart from their delusions, people with delusional disorder may continue to socialize and function in a normal manner and their behavior does not generally seem odd or bizarre to others for many years of the onset of their symptoms. Because of this, they are brought to the clinician many years after the onset of their symptoms, only when their delusional behavior becomes overt. Thus, identifying and treating delusional disorders in time is a challenging task.