Comparison to Autism and Asperger's

While PDA is increasingly recognised as being part of the autism spectrum there are some key differences from the presentation of those with more typical autism or Asperger's syndrome.PDA and its diagnostic criteria are regarded as more complex in comparison.

The following differences are significant at 0.001 level:

Children with PDA are LESS likely: 

  • to have caused anxiety to parents before 18 months of age
  • to show stereotypical motor mannerisms
  • to show (or have shown) echolalia or pronoun reversal
  • to show speech anomalies in terms of pragmatics
  • to show (or have shown) tiptoe walking
  • to show compulsive adherence to routines

Children with PDA are MORE likely:

  • to resist demands obsessively (100%)
  • to be socially manipulative (100% by age five)
  • to show normal eye contact
  • to show excessive lability of mood and impulsivity
  • to show social mimicry (includes gestures and personal style)
  • to show role play (more extended and complete than mimicry)
  • to show other types of symbolic play
  • to be female (50%)

The above data is taken from Pathological Demand Avoidance syndrome: Discriminant Functions analysis demonstrating its essential differences from autism and Asperger's syndrome: Elizabeth Newson and Kathryn le Marechal, Early Years Diagnostic Centre and University of Nottingham, England. Paper available from Autism East Midlands.

People with PDA can become obsessive about particular individuals or relationships. They tend to show a high level of impulsivity, excitability and sometimes violent behaviour, often associated with these obsessive interests, and occasionally involving harassment of another child or adult. Their obsessive interests are qualitatively different from those seen in autism / Asperger's.

Like all children with a pervasive developmental disorder, people with PDA will have certain communication problems, although these may be masked by their superficially high social skills of distraction and avoidance, thus the underlying deficits can be quite easily overlooked. Semantic pragmatic language (the social use of language, including body language) may also be affected, but not to the degree found in autism and Asperger syndrome. Bizarre content of language is more common than in autism, sometimes due to interest in fantasy.

Individuals with PDA tend to have over-active imagination as opposed to under-active, and this clearly sets them apart from Wing's description of the autistic Triad of Impairments. Individuals with PDA quite often become confused as to the boundaries of reality and imagination (as they also do with other boundaries). They may submerge themselves into characters that they have modelled themselves on, either from TV or from real life, and sometimes they can seem to have lost touch with their 'real' selves. Many children with PDA take on the role of their teacher in great detail, and will tell other children what to do (much to their annoyance!) Keeping the tolerance and sympathy of other children in the classroom can be a difficult task for teachers who are trying to meet the needs of a child with PDA.

Most of the characteristics mentioned tend to persist in various forms into adult life, but research in this area is not extensive at present. The prevalence of PDA compared with autism is not known.