In India the rates have varied: 5% cases of paranoia out of all patients with delusions Sriniva- psychiatric outpatients having delusional parasitosis e san et al, 1993, and 1% of the total outpatients having DD d including half with delusional parasitosis (Hebbar et. al, 1999). validity of Delusional Disorder In terms of relevance to the question of validity of DD the available data can be divided into three classes of potential validators (this schema represents an adaptation and enlargement of the validating criteria for psychiatric illness as outlined by Robin and Gaze, 1970): antecedent, concurrent and predictive validators (Table 2).