Pervasive Developmental Disorders

In some parts of the world autism and Asperger’s Disorder are seen in terms of the American Psychiatric Association’s Diagnostic and Statistical Manual (DSM-IV), which places autism and Asperger Syndrome within a group of Pervasive Developmental Disorders.

• Autism
• Asperger’s Disorder
• Childhood Disintegrative Disorder (Hellers Syndrome)
• Retts Disorder
• Pervasive Developmental Disorder (not otherwise specified)

Current thinking and research is coming around more to this view of the place of autism and Asperger Syndrome in a constellation of disorders of development.

 It is recently suggested that this list might be expanded to include:

• Atypical Autism
• Semantic-Pragmatic Disorder

And that overlaps include Attention Deficit Hyperactivity Disorder (ADHD), Dyspraxia and Dyslexia.

Causes of autism and Asperger syndrome (or PDD’s)

No one cause has been identified but rather it seems to be a combination of factors.  Certain medical conditions are implicated, such as:

• Congenital rubella and tuberous sclerosis
• Pre and perinatal trauma, and neonatal asphyxia
• Certain acquired encephalopathies and brain malformations
• Metabolic disorders such as phenylketonuria (PKU), histidaemia and Lesch-Nyan syndrome
• A number of genetic conditions and chromosomal abnormalities, including fragile X, De Lange syndrome, Joubert syndrome and Williams syndrome.

There is statistical support for inherited genetic factors.

There is some evidence from recent research into brain function that the amygdala is implicated in the causation of impairment of social skills.

Autism

Asperger Syndrome