Abstract
Assessment and diagnosis of autism in adulthood is a growing area of interest for both clinical and research practice. In thiscommentary, we present a thematic analysis following the first International Society for Autism Research Special Interest Group(SIG) focused on assessment and diagnosis of autism in adulthood. An increasing recognition of missed or misdiagnosed autisticadults is highlighted throughout the commentary. Recommendations for reducing barriers in diagnostic processes are reviewed,including improving existing adult autism measures and developing new ones, especially self-report/interview tools capturingwhat cannot be externally observed; providing more information about the process ahead of time and better post-diagnosticsupport; better assessment of psychosocial and mental health histories; training to promote clinicians' understanding of adultautism; and the importance of considering culture. Professional and government bodies should support the development of neu-roaffirming, client-centered practice guidelines that actively include input and co-design from autistic adults