Type of schizophrenia with mental retardation

Pfropf schizophrenia occurring in the presence of mental retardation .it differs from schizophrenia in only that there is often a povey of ideation and delusions are not usually very well systematised.therefore behavioural disturbances are more prominent than delusions and hallucinations Ref: A sho textbook of Psychiatry. Nihal Ahuja. Edition 7. Pg no:61