Autism Spectrum Conditions; the Age of, Recency of and Lack of Diagnosis

Very little is known about autism spectrum conditions in adulthood, especially those that are diagnosed late in life or self-diagnosed; let alone how they were not diagnosed earlier or at all. As a relatively new subset of autistic people, it is also unclear how the timing and recency of an autism diagnosis might affect an individual. This research explores relationships between a range of cognitive, behavioural and mental health variables and the age and recency of a person’s diagnosis or self-diagnosis to address three questions; 1. Do individuals who received a diagnosis of an ASC in childhood differ in a range of variables from those who realised they are autistic as adults? (the age of autism diagnosis) 2. Do those without official diagnoses differ from those with official diagnoses? (the lack of diagnosis) 3. What role, if any, does the time elapsed since diagnosis or self-diagnosis of ASC play in these results? (the recency of diagnosis). A total of 409 clinically diagnosed autistic and self-diagnosed autistic people participated across three separate online surveys. Consistent findings across all studies show relationships between autistic traits and the time elapsed since diagnosis, as well as significant differences between diagnosed and self-diagnosed participants in levels of autistic traits, as measured with both the Autism Spectrum Quotient and the short Ritvo Autism and Asperger Diagnostic Scale. A significant difference in working memory between those diagnosed aged 18 or younger and those diagnosed over 18 was also found. Also, levels of camouflaging were found to be higher in participants without an official diagnosis. Implications arising from this research include greater awareness of the diagnostic and post-diagnostic needs of autistic people across their lifespan.