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ADHD as Dimensional

ADHD is not a categorical “thing.”

Key points

  • ADHD is considered a neurodevelopmental syndrome of impaired self-regulation or executive dysfunction.
  • Features of ADHD do not represent a distinctive category, but instead fall along a dimension of human traits.
  • Recent research on children with ADHD traits demonstrates this sort of dimensional understanding of ADHD.
  • This dimensionality means symptom criteria are not rigid cutoffs; subthreshold ADHD can cause problems, too.

The contemporary view of ADHD is that it is a problem of impaired self-regulation by way of executive dysfunction, which results in life impairments—the pain points of adult ADHD.

In case it is not clear, everyone has executive functions. They are a feature of human functioning that unfolds developmentally. If you wake up to an alarm you set or can think through that second slice of cake and realize you do not need it, that’s self-regulation. On the other hand, if you suffer an extended period of sleeplessness, your executive functioning will go down. But, as your sleep returns to normal, via treatment or spontaneous improvement, your executive functioning will reset to its stable, intact state.

The issue with ADHD is that it is neurodevelopmental, not episodic. Executive functioning falls along a continuum of human functioning. Some individuals have well above average executive functioning that is on display in most settings and roles, an enviable consistency and reliability, even annoyingly so. Most people fall in the broad middle of the range.

Individuals with ADHD and its features—the core symptoms and executive dysfunction— reside at the problematic other end of the continuum. ADHD is a chronic delay in the onset and efficient use of self-regulation capacities and skills. This is what causes the vexing, inconsistent time management, disorganization, and wait-until-the-last-minute motivation that produces the many impairments associated with a history of ADHD.

Source: cottonbro studio / Pexels
The diagnosis of ADHD does not fit in a neat box and neither do the people who experience the range of its effects.
Source: cottonbro studio / Pexels

Recent research examining symptoms of ADHD has shown this sort of linear distribution along a continuum.1 Parent/caregiver’s ADHD symptom and psychosocial quality-of-life ratings were obtained for nearly two-thousand children (6-11 years old). Two percent of the sample had been diagnosed with ADHD and 5% of the children studied fell in the diagnostic range of the ADHD rating scale employed in the study, which is consistent with diagnostic rates for children. The linear distribution finding means that as symptom ratings went up, quality-of-life ratings went down steadily and predictably. Individuals with no or few symptoms of ADHD were rated with very good quality of life. As the reported number of symptoms of ADHD increased for the children, quality of life scores steadily decreased, the lowest ratings by children with the highest number of ADHD symptoms, a linear progression. If ADHD were a distinct “thing” that you “got,” there would be a clear-cut drop in such ratings, a sudden marked drop like going off a cliff, akin to a sudden drop in blood pressure for a medical condition.

The diagnostic line of what constitutes a disorder in such cases is hard to draw and can be critiqued as arbitrary, as is often voiced by ADHD critics. But arbitrary lines drawn in healthcare are not meaningless or haphazard. Diagnostic thresholds using symptoms for ADHD (combined with verification of impairments and other criteria) sit alongside lines drawn for hypertension and various blood test results.

The findings of this study reinforce a dimensional view of ADHD; its difficulties are a matter of degree of problems related to its features versus a distinct kind of problem or disease. This also highlights that the dividing line for the diagnosis should not be a rigid, definitive cutoff point. Indeed, these findings shed light on the potential difficulties faced by individuals with impairments from subthreshold ADHD presentations.

As Edmund Burke said of the dividing line between day and night (cited in “Driven to Distraction”)2: “(T)hough there be not a clear line between them, yet no one would deny that there is a difference” (p. 195).


1 Arildskov, T. W. et al. (2024). Is Attention-Deficit/Hyperactivity Disorder (ADHD) a dimension or a category? What does the relationship between ADHD traits and psychosocial quality of life tell us? Journal of Attention Disorders, online ahead of print.

2 Hallowell, E. M, & Ratey, J. J. (1994). Driven to distraction. Touchstone.

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