WHAT ARE SYMPTOMS OF THE OTHER PERVASIVE DEVELOPMENTAL DISORDERS?
RETT’S DISORDER differs from Autism primarily in that it is associated with loss of previously acquired hand skills between ages 5 months and 30 months and onset of severe or profound mental retardation. Motor skills are replaced with repetitive movements of the hands. According to the DSM-IV the diagnostic features of RETT’S DISORDER are as follows: Apparently normal prenatal and perinatal development Apparently normal psychomotor development through the first 5 months after birth CHILDHOOD DISINTEGRATIVE DISORDER is diagnosed when a child shows a clinically significant loss of previously acquired skills in verbal and nonverbal communication, social relationships, play, and adaptive behavior, after the first 2 years of life (but before age 10 years.) Both RETT’S DISORDER and CHILDHOOD DISINTEGRATIVE DISORDER appear to be very rare. Little behavioral research has been conducted in persons who have these diagnoses. According to the DSM-IV the diagnostic features of CHILDHOOD DISINTEGRAT
