The coexistence of Attention Deficit Hyperactivity Disorder (ADHD) and high intelligence has been controversial, often hindering diagnostic accuracy and therapeutic targeting. The article reviewed by Rommelse et al. (2022) offers a systematic synthesis of neurobiological, behavioral, and genetic findings on ADHD in individuals with significantly high intelligence, based on the diagnostic validity criteria originally proposed by Robins and Guze (1970) and adapted by Faraone (2005).
Under the first criterion—whether ADHD symptoms can be dissociated from common behavioral traits in highly intelligent individuals—the data suggest that symptoms such as inattention and impulsivity are less prevalent in this population, while hyperactivity tends to be present at normal to high levels. This indicates that hyperactivity may be a behavioral manifestation of giftedness and not necessarily a pathological marker. This pattern reinforces the hypothesis that, in these cases, hyperactivity has an adaptive function, related to the increased search for cognitive and sensory stimuli. However, the lack of systematic data on the degree of functional impairment generated by such behaviors limits diagnostic generalization (Rommelse et al., 2022).
Regarding the evolutionary trajectory of the disorder, individuals with ADHD and high IQ presented rates of syndromic persistence similar to those of people with average intelligence. Furthermore, they reported a greater need for school support, increased psychiatric comorbidities and functional impairments in family and occupational domains, showing that high intelligence does not eliminate the impacts of ADHD throughout life (Antshel et al., 2007; 2008; 2009 apud Rommelse et al., 2022).
From a neuropsychological perspective, the authors observed that cognitive abilities such as sustained attention, working memory, response inhibition, and processing speed tend to be superior in individuals with high intelligence. In contrast, such functions are consistently impaired in people with ADHD. In cases where both profiles coexist, cognitive deficits are often masked by high overall performance, which reinforces the need for neuropsychological assessments that consider the discrepancy between estimated intelligence and performance on specific tasks. Available studies indicate that these individuals perform in a manner compatible with controls without ADHD of average intelligence, but below that expected for their level of intelligence — which suggests a real manifestation of the disorder, although partially compensated by the cognitive repertoire (Rommelse et al., 2022).
Genetically, although both IQ and ADHD show significant heritability, the reviewed studies indicate modest genetic overlap between the two constructs. In the specific case of individuals with high IQ and ADHD, the familial recurrence rate was similar to that observed in ADHD samples of average intelligence, suggesting that the inheritance mechanisms are not distinct (Antshel et al., 2007, 2009 apud Rommelse et al., 2022).
Finally, regarding response to treatment, available evidence shows that individuals with ADHD and high IQ respond similarly to pharmacological treatment compared to those with average IQ. This contradicts the idea that their high intelligence alone significantly modulate therapeutic efficacy, pointing to the need for equally structured interventions (Grizenko et al., 2012 apud Rommelse et al., 2022).
In summary, the reviewed data reinforce the validity of the diagnosis of ADHD in individuals with high intelligence, as long as the diagnosis takes into account the possible attenuation or masking of symptoms and the variability in the criteria for giftedness. The hypothesis that hyperactivity may have adaptive value in this context is intriguing, especially in light of a more flexible neurodevelopmental model that considers divergent trajectories of cortical maturation. As a neuroscientist, I realize that we still lack longitudinal studies with more rigorous designs to understand the interactions between higher cognition and psychopathology—a fertile ground for future research.
Reference:ROMMELSE, N.; VAN DER KRUIJS, M.; DAMHUIS, J.; HOEK, I.; SMEETS, S.; ANTSHEL, K.; HOOGEVEEN, L.; FARAONE, S. A neuroscience perspective on the validity of attention-deficit/hyperactivity disorder in the context of (very) high intelligence. 2022. Unpublished manuscript.
