Case Report: Autism-like phenomenology in functional neurological disorder in the social-media era: over- and under-diagnosis of autism as a bidirectional clinical problem.

Social media increasingly influence how adolescents and young adults understand and communicate neuropsychiatric symptoms, including symptoms attributed to autism spectrum disorder (ASD). This creates a particular diagnostic challenge in functional neurological disorder (FND), a condition in which neurological symptoms are genuine and disabling but are understood as arising from altered nervous-system functioning rather than structural neurological disease. Recent literature indicates that FND and ASD co-occur more often than would be expected by chance, although estimates vary substantially across studies and clinical populations. At the same time, autistic-like features such as sensory hypersensitivity, social difficulties, alexithymia, and altered interoceptive processing may occur across diagnostic boundaries and may therefore complicate differential diagnosis. The present case concerns a 17-year-old female patient with complex FND and prominent autistic-like phenomenology who attributed her difficulties to ASD largely through social-media exposure, while standardized assessment and retrospective developmental history did not support an ASD diagnosis. The case therefore provides an opportunity to examine two related but distinct questions: how genuine ASD may co-occur with FND, and how autistic-like experiences may arise in patients with FND without a developmental basis for ASD. We further consider whether, in a subset of patients, such phenomenology could represent a functionally mediated cognitive-behavioural construct shaped by predictive processing, interoception, alexithymia, and exposure to diagnostic narratives.