Pervasive Developm
Pervasive Developmental Disorder - Not Otherwise Specified (PDD-NOS)
The diagnosis of PDD-NOS is appropriate when there is severe and pervasive impairment in the development of reciprocal social interaction associated with impairment in either verbal or nonverbal communication skills or with the presence of stereotyped behavior, interests, and activities, but the criteria are not met for a more specific disorder. This diagnosis is often used when a child shows several symptoms consistent with an ASD, but does not meet the full criteria for either Autistic Disorder or Asperger’s Disorder.
Other Pervasive Developmental Disorders
The essential feature of Childhood Disintegrative Disorder is a marked regression in multiple areas of functioning following a period of at least 2 years of apparently normal development. After the first 2 years of life (but before age 10), the child shows a clinically significant loss of previously acquired skills in at least two of the following areas: expressive or receptive language, social skills or adaptive behavior, bowel or bladder control, play, or motor skills. Rett’s Disorder or Rett Syndrome, which is a genetic disorder that occurs almost exclusively in girls, involves the development of multiple specific deficits following a period of normal early functioning. Between 5 and 48 months of age, the child with Rett Syndrome shows a slowing of head growth, loss of previously acquired purposeful hand skills, the development of stereotyped hand movements (e.g., hand wringing), a loss of social engagement, poorly coordinated gait or trunk movements, and severely impaired language and psychomotor skills.
Causes of Autism
No one knows for sure what causes autism, but scientists believe that both genes and the environment play a role. Research has shown that autism tends to run in families. Among identical twins, if one child has autism, then the other is likely to be affected 75-90% of the time. Parents who have a child with an ASD have a 2-10% chance of having a second child who is also affected. Some parents worry that vaccines cause autism, but the scientific evidence does not support this theory. There is some evidence that exposure to factors in the environment (such as viruses or infections) may play a role in causing some forms of autism. It is important to recognize that autism is a brain-based disorder and is not caused by inadequate parenting; however, parents can play an important role in planning and carrying out interventions after an ASD is identified.
