Referral for ASD diagnostic assessments in the cases where ASD is not the primary cause for a child's difficulties increases pressure on assessment services, can delay access to ASD-specific intervention services for children who do have ASD, and can contribute to parent anxiety unnecessarily. The current evidence that a substantial minority of children were referred for ASD diagnostic assessments when ASD was not the primary cause for the difficulties emphasises the value of adopting a developmental differences framework, focusing on dimensions of behaviour and functioning, rather than an autism-specific service structure.