This paper examines, from a psychological perspective, why some young people may diagnose themselves with a mental health condition or neurodevelopmental difference after engaging with TikTok content. The article joins the discourse around TikTok self-diagnosis among adolescents, which has circulated since 2022, and offers alternative considerations and perspectives. The reasons a young person may self-diagnose are complicated and multifaceted, extending beyond any explanation of naivety or attention-seeking. In this paper the phenomenon is approached through an application of social psychological theories relating to identity, belonging, and self-labelling. The broader context is considered against the backdrop of the neurodiversity movement and corresponding cultural shift, with reference to the intersecting systemic barriers faced by young people which impede the availability and accessibility of adequate support. Opportunities for future research and suggestions for how educational psychologists may consider online environments within professional practice are discussed.