A pervasive developmental disorder (PDD) is characterized by developmental delays in social and communication skills.[1]
Pervasive developmental disorders is a diagnostic category which refers to a number of related disorders:
Symptoms may appear as early as infancy. Typically the age of onset is before 3 years of age.
Symptoms may include
Children with PDD vary widely in abilities, intelligence, and behaviors. Speech may be very limited or completely absent. Some children, on the other hand, have relatively normal language development. Repetitive behaviour and limited social skills are generally evident. PDD children may also demonstrate unusual responses to sensory stimulation, such as loud noises and lights.