PDA (Pathological Demand Avoidance) is widely understood to be a profile on the autism spectrum.
This is an incredibly informative and useful website, I strongly suggest perusing their pages to find out more about PDA and how you can support people with PDA and disseminate knowledge.
Information and support strategies for adults, parents, carers, and professionals
National Autistic Society
Another very useful website that will also give you a greater understanding of how PDA fits into the Autistic Spectrum.