The Delphi (2024) Definition of Dyslexia

In 2024, an international panel used the Delphi method—a structured, anonymous, multi‑round survey—to refine dyslexia’s consensus definition. They agreed that dyslexia is “a set of processing difficulties that affect the acquisition of reading and spelling,” with core phonological processing deficits (awareness, speed, memory) and additional contributions from working memory, processing speed, and orthographic skills.

Key updates include a stronger emphasis on reading fluency—especially for teens and adults who compensate at the word level—and clear recognition that dyslexia exists on a continuum of severity. The definition applies across all ages and highlights the roles of genetic and environmental influences. It also calls attention to common co‑occurring conditions (e.g., ADHD, language disorders) and secondary impacts like anxiety or low self‑esteem.

For assessment, professionals should ensure their batteries measure phonological skills, rapid naming, working memory, processing speed, and orthographic processing, and update reports to reference the Delphi consensus. Intervention remains grounded in evidence‑based phonological programs but should also include fluency practice, orthographic training, and supports for memory and speed (mnemonics, text‑to‑speech). Accommodations—extra time, assistive technology tools, workplace adjustments—must be tailored across the lifespan.

By aligning practices with the 2024 Delphi definition, assessors can offer clearer, more consistent, and more effective support for individuals with dyslexia.