During the 1970s we saw a number of children who “reminded” their medical referrers of autism, but were clearly not typical of autism. Sometimes autism was rejected or questioned because of the child’s imaginative ability, especially in non-echolalic role play; often the child seemed unusually sociable, though in an “odd” way, and language development was atypical of autism and less pragmatically disordered than in Asperger’s syndrome. We, like others, were diagnosing these children as having atypical autism (stating in what way it was atypical); and we were not alone in being disbelieved by parents when they met children diagnosed as autistic, nor in having our diagnosis undermined by teachers who did not recognise any autistic connection.
Aware of the unsatisfactory nature of the “atypical autism” label, we also began to notice that B reminded us of A, who also had something in common with C. After six years we had a cohort of 21 children who were “atypically autistic” but were also typical of each other. Not least unusual about them (as an “autistic” group) was the sex ratio: 15 of them were girls. Obviously sex ratios cannot be trusted where small numbers are involved, and these proportions equalised as we reached 150 cases (75 male, 75 female); they remain highly significantly different from sex ratios in autism.
An analysis was made, distinguishing features which all 21 children in this first cohort shared from those which were frequent but not invariable.1,2 Some which were expected to be merely background features turned out to be held in common more than we had realised: notably symbolic play (especially doll play and role play), and at least “soft” neurological signs. The central salient characteristic of all 21, which made them strikingly difficult for their parents and teachers, was an obsessional avoidance of the ordinary demands of life coupled with a degree of sociability that allowed social manipulation as a major skill. Despite our reluctance to use the word “manipulative” in speaking of children, it was impossible not to recognise this shared quality, especially as it contrasted so clearly with autistic children.
A name for this “different” pervasive developmental disorder seemed essential, for the usual reasons of easy referral and agreed meaning, but especially in order to be descriptive.3Pathological demand avoidance syndrome was chosen (admittedly under pressure from an impending paediatric lecture), and now has wide recognition as a clinically useful concept. Despite the criticisms that can be made, this name has the major advantage that when doctors, psychologists, and teachers encounter the truly pathological degree of “demand avoidance” that the condition always involves on a long term basis, they are increasingly likely to consider the diagnosis, rather than blame parents or child for “unsocialised” behaviour. This has already saved some families years of bewilderment, through earlier recognition. With a name and a criterial structure, we were able to rediagnose earlier children; and parents would confess, after perhaps five years: “Autism never made sense to us; this is the first time a diagnosis has made sense”.
An equally important reason for needing the separate diagnostic term proved to be the different needs of the child with PDA. Specialist schools for “autistic” children, which include one or two with PDA, immediately discover the enormous difficulties posed by a child who is deeply threatened by educational demands and organisational rules. The guidelines that are successful with autistic children need major adaptations for PDA children if any progress is to be made; these children hate routine and thrive best on novelty and variety. If perceived as ASD children, the wrong advice will be given: PDA children suffer a high exclusion rate if educated on autistic guidelines, as do young adults. This must be a powerful reason for a differential diagnosis, especially once we are able to articulate guidelines which are positively helpful for children with PDA. http://adc.bmj.com/content/88/7/595.full