Adult ADHD as a Potential Risk Factor for Dementia: A Scoping Review
Lia Reyes Santos1, Marcos Brea Montes de Oca2, Sherly Baez Arias3, Diego Gil Troncoso2, Chanel Reyes2, Rossmery Montaño Cabreja4, Gelanys Castro Tejada5, Natanael Duarte6, Rey Nuez Lopez7, María Cedeño-Bruzual2
1Clinical Trials, Oncology Research Center (ONCONET), 2Research Department, Centros de Diagnóstico y Medicina Avanzada y de Conferencias Médicas y Telemedicina (CEDIMAT), 3School of Medicine, Universidad Autónoma De Santo Domingo, 4Research Department, Instituto Dermatológico y Cirugía de Piel Dr. Huberto Bogaert Díaz, 5Department of Neurology, Westchester Medical Center, 6Department of Medicine, Holy Name Medical Center, 7School of Medicine, Universidad Tecnológica de Santiago
Objective:

To collect and describe available literature exploring the association between adult ADHD and the risk of developing dementia.



Background:

Attention-deficit/hyperactivity disorder (ADHD) often persists into adulthood. Emergent studies suggest an association between adult ADHD and dementia. However, longitudinal data assessing whether ADHD influences dementia risk remain scarce.



Design/Methods:

A scoping review was performed following PRISMA-ScR guidelines. PubMed/MEDLINE, Scopus, EMBASE, and PsychINFO were searched for English- and Spanish-language studies (2010-2025). Eligible designs included cohort, case-control, and cross-sectional studies; preclinical and pediatric population studies were excluded. Screening was performed in Covidence. Outcomes evaluated: ADHD-treatment history, global cognition, domain scores, and dementia incidence/prevalence.



Results:

Seven studies (n=2,683,190) were included: five cohorts, one case-control, and one cross-sectional. All studies compared adults with ADHD to matched controls with 5–17 years of follow-up. Diagnoses were established via clinical assessment, validated tests, and ICD codes. Four cohorts found elevated dementia incidence in ADHD, with HRs ranging from 2.77 to 4.01, all statistically significant. A multigenerational cohort showed increased parental dementia risk (HR 1.55, 95% CI 1.26–1.89, p<.001). Two studies associated ADHD with Lewy Body Dementia (IRR 1.21, 95% CI 1.08–1.35, p<.001; OR 5.1, 95% CI 2.7–9.6, p<.001), and one with Alzheimer’s disease (IRR 1.15, 95% CI 1.05–1.27, p<.001). Three studies reported Mini-Mental State Examination scores, consistently lower among ADHD patients (means 21.7–28.5). One study found no significant protective association of ADHD treatment with dementia risk.



Conclusions:

Adults with ADHD exhibit a higher risk of dementia across diverse populations, though heterogeneity in diagnosis and limited treatment evidence highlight the need for rigorous longitudinal research.


10.1212/WNL.0000000000213008
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