AuDHD in Females: Characterisation, Prevalence and Implications for Management

It is now known that when autistic spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD) occur together the comorbid condition is more difficult to manage than either alone. In females masking and diagnostic overshadowing of both conditions, combined with the fact that ADHD in females appears to be largely inattentive, makes the combined condition more challenging for the clinician and the subject alike. It is only known by an acronym, AuDHD, is not yet a formally recognised mental health condition, and the aforementioned recognition problems make its true prevalence unknown. This also leads to an underestimate of how commonly ASD occurs in the female ADHD population and these unknowns lead to significant management problems. The indirect but potentially accurate way to find the unknowns is by Bayes’ theorem, and the independent variables used to find the unknown dependent variables were established from the author’s 2014-2022 clinical cohort of 794 autistic females under the age of 18, combined with published data. Due to the extensive masking and overshadowing of the prevalence of ASD in both the overall population and the ADHD population, the true prevalence of AuDHD appears to be about 25 times the reported prevalence. The effectiveness of ADHD medications in AuDHD was measured as were the relative proportion of internalising and externalising behaviours. The implications of these results for management are discussed. In assessing the degree of overshadowing, a value for overshadowing in males with ASD has been derived for the first time.