Blood-based biomarkers offer an important opportunity to improve the investigation of cognitive impairment. In a Swedish study involving 1,213 people with cognitive symptoms, selected plasma biomarker approaches identified Alzheimer’s disease pathology with high diagnostic accuracy in primary and secondary care [1]. That achievement deserves recognition. It also raises a practical question: what happens after the result? A test for pathology cannot, on its own, describe the cognitive difficulties that brought someone to a clinic or the support they need at home. The Alzheimer’s Association’s 2025 guideline supports blood tests with at least 90% sensitivity and 75% specificity for triage, and tests meeting 90% for both measures as substitutes for amyloid positron emission tomography or cerebrospinal fluid biomarker testing. These conditional recommendations are based on low-certainty evidence and concern people with objective cognitive impairment in specialised care; they are not an endorsement of every available assay or population screening [2]. Replacing another method of detecting pathology is not equivalent to replacing the assessment of cognition and functioning. This distinction remains important within a biological definition of Alzheimer’s disease. The 2024 revised criteria allow diagnosis using sufficiently accurate core biomarkers while distinguishing biological stage from clinical severity. Cognitive reserve and coexisting pathologies can modify the relationship between the two [3]. A positive biomarker result therefore does not, by itself, establish dementia. Nor does it show which activities have become difficult or which abilities remain preserved. Those are questions about the clinical expression of disease, not objections to its biological definition. Neuropsychological assessment provides information that a molecular measurement does not. It examines the pattern of difficulties across learning, memory, language and other cognitive domains, interpreted alongside the person’s history, mood and educational and linguistic background. It can clarify subtle or atypical presentations, establish a baseline for assessing change and identify preserved abilities that may support compensatory strategies [4]. Its purpose is not simply to produce a score that agrees with a biomarker. It is to explain the person’s cognitive profile and help translate that understanding into practical recommendations. This does not mean that a lengthy test battery should become a prerequisite for every blood test. Assessment should be proportionate to the clinical question. A careful history, an appropriate validated cognitive measure and an account of daily functioning should inform the diagnostic pathway. Formal neuropsychological evaluation is particularly useful when the history and brief testing do not agree, the presentation is complex or important diagnostic questions remain unresolved [5]. The aim is timely access to the expertise a person needs, rather than another compulsory appointment for everyone. Communication also belongs within the pathway, not after it. Patients should understand what a proposed test can establish, what uncertainty may remain and how its result could affect care [2,5]. A negative result for Alzheimer pathology should not end the investigation of persistent cognitive symptoms. A positive result should lead to an explanation that incorporates cognitive and functional findings, rather than an isolated laboratory label [3,5]. Results need to be linked to an agreed plan for further assessment, treatment consideration or support. Services adopting blood-based testing should therefore evaluate more than diagnostic accuracy and the number of samples processed. Relevant outcomes include whether patients understand their results, receive appropriate follow-up and obtain help with the difficulties that prompted assessment. This is also a research priority: implementation studies should test whether more accessible biological diagnosis produces better-informed decisions and more useful care. The clinical value of a biomarker lies not only in the pathology it identifies, but in the decisions it helps patients and clinicians make. Blood-based testing should strengthen the assessment of cognition and everyday functioning, not displace it.

Keywords: Cognitive Stimulation Therapy; Mild Cognitive Impairment; Montreal Cognitive Assessment; Non-Pharmacological Interven- tion; Cognitive Rehabilitation

1. Palmqvist Sebastian, et al. “Blood biomarkers to detect Alzheimer disease in primary care and secondary care”. Journal of the American Medical Association15 (2024): 1245-1257.
2. Palmqvist Sebastian., et al. “Alzheimer’s association clinical practice guideline on the use of blood-based biomarkers in the diagnostic workup of suspected Alzheimer’s disease within specialized care settings”. Alzheimer’s and Dementia7 (2025): e70535.
3. Jack Clifford R Jr., et al. “Revised criteria for diagnosis and staging of Alzheimer’s disease: Alzheimer’s association workgroup”. Alzheimer’s and Dementia8 (2024): 5143-5169.
4. Shaughnessy Lynn W and Sandra Weintraub. “The role of neuropsychological assessment in the evaluation of patients with cognitive-behavioral change due to suspected Alzheimer’s disease and other causes of cognitive impairment and dementia”. Alzheimer’s and Dementia1 (2025): e14363.
5. Dickerson Bradford C., et al. “The Alzheimer’s association clinical practice guideline for the diagnostic evaluation, testing, counseling, and disclosure of suspected Alzheimer’s disease and related disorders (DETeCD-ADRD): Executive summary of recommendations for specialty care”. Alzheimer’s and Dementia1 (2025): e14337.