1 Department of Psychology, SP244, Concordia University, 7141 Sherbrooke St. West, H4B 1R6, Montréal, Canada. zoey.stark@mail.concordia.ca.
2 Department of Psychology, SP244, Concordia University, 7141 Sherbrooke St. West, H4B 1R6, Montréal, Canada.
3 CRIR/Centre de Réadaptation MAB-Mackay du CIUSSS du Centre-Ouest-de-l'Île-de-Montréal, Montréal, Canada.

Dyslexia is a neurobiological disorder characterized by persistent difficulties in reading, writing and spelling. Studying adults with dyslexia is challenging due to diverse experiences, varying ages of diagnosis and potential comorbidities. This study utilized a mixed-method approach to explore how the timing and occurrence of a dyslexia diagnosis influence individuals' experiences. Descriptive analysis revealed heterogeneous responses concerning age of diagnosis and overall experience, with predictor variables including perceived reading severity, family dyslexia diagnosis, comorbidities and self-perceptions of disability, intelligence, frustration, laziness, empowerment and self-restraint. To further investigate these associations, three classification and regression trees (CART) were constructed, showing that individuals diagnosed early or late without comorbidities were more likely to report positive or neutral experiences. A qualitative reflexive thematic analysis identified six themes: (1) internalizing effects of dyslexia, (2) perceived experience of dyslexia, (3) perceived perception by others, (4) shifts in experience over time, (5) acceptance and (6) coping skills. These qualitative findings complemented the descriptive and CART results, providing a comprehensive understanding of dyslexia experiences and secondary effects based on the age of diagnosis. This combined analysis underscores the importance of early diagnosis and the absence of comorbidities in shaping positive outcomes for individuals with dyslexia.