Here is a scenario playing out in clinics across the country: an older adult walks in reporting trouble with memory and mental processing. Their physician, reasonably, considers early dementia. The tests begin. The wait is agonizing. But what if the root cause is something else entirely — a condition written off as a childhood problem decades ago?
A new study published in the Journal of Attention Disorders adds important evidence to a growing concern in geriatric medicine: undiagnosed or unmanaged ADHD in older adults may be masquerading as early cognitive decline, and the two are remarkably difficult to distinguish from symptom descriptions alone.
Marrium Mansoor at Virginia Tech led the research, which drew on data from approximately 1,300 American adults over 50 participating in the Health and Retirement Study — a large, nationally representative dataset that gives the findings real statistical weight. Participants were divided into three age bands: 55-64, 65-74, and 75-84. Each completed the Adult ADHD Self-Report Scale alongside a battery of cognitive tests covering working memory (Serial 7s), episodic recall, and fluid intelligence.
The central finding is striking in its consistency: inattention symptoms were reliably associated with lower performance across all three cognitive domains — and this association held across every age group tested. An 84-year-old with high inattention scores showed the same pattern of cognitive underperformance as a 55-year-old with the same profile. Critically, the effect was specific to inattention — hyperactivity and impulsivity showed far less consistent relationships with cognitive outcomes. Depression, a common confound in both ADHD and dementia research, was ruled out as the primary driver.
This matters clinically for a straightforward reason. The cognitive fingerprint of inattentive ADHD — poor working memory, slower processing speed, weaker episodic recall — overlaps substantially with the early signs of neurodegenerative disease. A clinician who does not think to screen for ADHD in a 70-year-old may never consider the possibility, especially given how thoroughly the condition has been framed as paediatric medicine.
The implications for misdiagnosis are real. Interventions developed for ADHD — mnemonic strategies, structured routines, targeted pharmacology — are distinct from dementia care pathways. Getting the diagnosis right determines the treatment direction. For older adults currently sitting in waiting rooms wondering why their memory keeps failing them, that distinction could be genuinely consequential.
