Commentary: PDA - what's in a name? Dimensions of difficulty in children reported to have an ASD and features of extreme/pathological demand avoidance: a commentary on O'Nions et al. (2017).

Pathological demand avoidance (PDA), a term first used by Elizabeth Newson in the 1980s, refers to a collection of behaviours that children will demonstrate to avoid instructions (and tasks) that they perceive as demands. These children are postulated to be averse to anything that is perceived as a demand placed on them. PDA features are commonly encountered in children with autism but PDA is not a subtype of autism nor a separately diagnosed mental, behavioural or developmental disorder in any of the major classification systems (ICD-10 or DSM-5). Such behaviours are not confined to children with autism and debate continues regarding its existence as a distinct phenomenon and if such a phenotype exists whether it is merely a part of autism or a separate condition. We comment on O'Nions and colleagues' study that explores common themes/behavioural traits in children with autism spectrum disorder (ASD) who also fit the phenotypic description of PDA. We explore how the current classification systems capture features of PDA in autism with diagnoses of common comorbidities in ASD (such as disruptive behaviour/conduct disorders, OCD and anxiety), but to many clinicians and parents this seems an inadequate description. What remains to be explored are the trans-diagnostic temperamental and cognitive traits of children with PDA features, such as cognitive rigidity and intolerance of uncertainty. It is important to understand why some children are demand avoidant and identification of these factors (individual and systemic) helps in management much more than classifying them with an additional label. O'Nions et al. have helpfully provided further insight into several underpinning traits/dimensions of children with PDA features; understanding these will help develop effective strategies for parenting demand-avoidant children.