ADHDn

ADHDn is a term used in some research and clinical discussions to refer to a proposed variant or related condition to attention-deficit/hyperactivity disorder (ADHD). It is not officially recognized in major diagnostic manuals such as the DSM-5-TR or ICD-11, and there is no standardized diagnostic criteria. The term is not widely adopted, and its meaning varies across sources. In some accounts, ADHDn is described as capturing heterogeneity within ADHD or as a distinct neurodevelopmental profile that may involve different cognitive patterns or symptom presentations. There is no consensus on its boundaries, prevalence, or clinical implications.

Proposals about ADHDn have included hypotheses about greater variability in executive function, working memory, and processing speed, or unique neural correlates; others suggest that ADHDn may reflect comorbidity, developmental stage, or measurement artifacts rather than a separate disorder. Because there are no validated criteria, diagnosis would generally rely on established ADHD assessments and careful consideration of other conditions. If used, ADHDn labeling should be used cautiously and as a tentative descriptor in research or case formulations rather than a formal diagnosis.

Clinical implications are uncertain. Some researchers argue that recognizing ADHDn could help explain within-ADHD variability and guide personalized interventions, while others warn that it could confuse diagnosis and complicate treatment planning. Presently, most evidence is exploratory and derived from small studies or theoretical discussions.

See also: Attention-deficit/hyperactivity disorder; neurodevelopmental disorders; diagnostic classification; heterogeneity in ADHD.