Francesca Happé is Professor of Cognitive Neuroscience and Director of the MRC’s Social, Genetic and Developmental Psychiatry Centre at the Institute of Psychiatry, King’s College London. She is also a board member and past-president president of the International Society for Autism Research. As part of my work on a wider feature on PDA and women and girls on the autism spectrum, Francesca kindly took some time to answer questions about her work.
What are your thoughts concerning autism in girls and women?
There is increasing interest in differences in manifestation by gender. Anecdotally/clinically many women with autism spectrum condition (ASC) describe using ‘masking’ strategies such as copying (clothing, behaviour, voice) a specific female peer at school or work — which I haven’t come across amongst men with ASC. There is also the impression that special interests in females with ASC are less unusual in focus (e.g., horses or pop stars versus electricity pylons, abstruse facts), although still unusually intense and narrow.
We’ve published two pieces of research so far that are relevant. One, led by Elise Robinson, showed that (male or female) siblings of females with ASC/high ASC traits were themselves more likely to have high ASC traits, compared to the siblings of males with ASC/high ASC traits (doi: 10.1073/pnas.1211070110). This supports the ‘female protective effect’ hypothesis; that females need a greater etiological dose (here explored in terms of genetic factors, as reflected in siblings) in order to manifest ASC.
The second study, led by Katharina Dworzynski, compared children high in ASC traits who did versus did not have an autism spectrum disorder (ASD) diagnosis (doi: 10.1016/j.jaac.2012.05.018). She found that girls who met diagnostic criteria were more likely to also have low IQ or additional behaviour problems (spotted by teachers, especially externalising problems) than girls equally high in ASC traits but without a diagnosis. No such difference existed between boys with versus without diagnosis. These findings could mean that high-functioning ASC girls without additional problems can compensate well, or that current diagnostic processes are missing girls with ASC unless they have extra flags to bring them to attention (such as low IQ). We have just submitted a grant application to try to find out which of these is the case, through more detailed and qualitative work with women with ASD/high ASC traits.
Do you see a relationship between PDA and the female presentation of autism?
One of the ideas we began with was that PDA might be a female manifestation of autism spectrum conditions. Without a large scale study comparing males and females with and without extreme demand avoidance, we can’t have a definitive answer, but we certainly found plenty of boys with demand avoidance in our research so far.
Could you briefly summarise our neurological understanding of autism?
That’s a big question! Briefly; genetic factors are known to be important in many cases — in a minority this may be an identified rare mutation, but in many cases it’s likely that many different genes of small effect operate together to influence high ASC traits/ASD. Many genetic and also neurological studies are under-powered (sample size too small) and hence there are many un-replicated findings. Better replicated findings include: signs of subtle differences in the brain that date back to the first trimester of pregnancy; rapid head/brain growth in the first four years of life in a subset of individuals with ASD; a great deal of interest in synaptic differences such as inhibitory/excitatory imbalance.
PDA is increasingly recognised in the UK, but where are we internationally?
PDA doesn’t seem to have travelled outside the UK as a concept or label yet. When I visit other countries I try to ask what they would call the pattern of extreme demand avoidance we call PDA here. Different places have different sorts of labels, often around either ASD or ‘oppositional defiant disorder’ (e.g., ‘the non-compliant child’). For PDA as a term to enter diagnostic manuals, a great deal more research evidence would be needed; Liz’s work is an important start (doi: 10.1177/1362361313481861; doi: 10.1111/jcpp.12149).
What do you see as the greatest challenges faced by those with PDA?
One of the biggest motivations for our research was hearing from parents, teachers and clinicians about young people with PDA who were excluded even from specialist autism schools, and who were the hardest to know how to teach despite apparently good intellectual capacity. If the usual ASC-friendly settings and approaches don’t work, it’s vital to find out what will.
We’ve made a small step towards establishing PDA in the research literature and examining some underlying cognitive processes. Liz has been valiant in collecting information and task performance from young people who, by definition, are hard to assess! We’re still some way off knowing what will work best for these young people; it would be wonderful to get empirical evidence from proper trials.
Learn more about autism from the National Autistic Society or watch Francesca’s talk, What We Do, Don’t and Must Know About Autism Spectrum Conditions.
Pathological Demand Avoidance syndrome (PDA) was first detailed by Elizabeth Newson in the 1980s to describe children who displayed characteristics of autism, but who were also obsessively resistant to ordinary demands and requests. Newson noted these children were surprisingly adept at using socially manipulative strategies, such as distraction or charm, to get round people. Though Newson described this group as ‘superficially sociable’, they lacked pride, embarrassment or a sense of responsibility to others. Many were also said to identify themselves as an adult, and were unable to negotiate with others their own age. Extreme changes in mood, such as sudden changes from calm to aggressive behaviour were also noted. Some of the children were also described as being comfortable in role-play and would get lost in role as if they had “become” that persona.
Read my interview with PDA activist Julia Daunt, or learn more about PDA here,here and here. Or visit the PDA Society website. If you’d like to know more about what it’s like to live with PDA, Steph Curtis has 14 recent case studies on her blog.