Cognitive Assessment and Functional Impairment in Dementia

Dementia is characterised by progressive decline in cognitive domains—memory, executive function, language and visuospatial skills—and by the resulting loss of ability to perform everyday tasks. Accurate assessment of cognitive status is essential for diagnosis, prognosis and monitoring of therapeutic interventions. Traditional neuropsychological batteries measure discrete cognitive functions, while performance-based and informant‐rated questionnaires capture the real‐world impact of deficits on instrumental activities of daily living (IADL). Recent advances combine fluid biomarkers, neuroimaging and digital platforms to enhance sensitivity to early changes and to map trajectories across the preclinical, prodromal and dementia stages. A multidimensional approach integrates structural and molecular imaging of cerebral amyloid and tau, blood‐based markers of neurodegeneration and standardised functional scales, yielding a more complete picture of disease progression. Harmonisation of assessment protocols across centres and the adoption of remote testing methods have expanded opportunities for longitudinal monitoring in diverse clinical and community settings. Such integrated strategies not only improve diagnostic accuracy and the prediction of conversion from mild cognitive impairment (MCI) to dementia but also enable evaluation of real‐world treatment effectiveness and health‐economic outcomes. Globally, these developments support earlier intervention, personalised care planning and the design of clinical trials targeted at individuals in the mild or pre‐symptomatic stages, where preservation of functional independence remains achievable.

Research from Nature Portfolio

A recent pilot study in a population‐based biobank demonstrated the feasibility of systematic recall of individuals with registry‐confirmed Alzheimer’s disease and mild cognitive disorder for in‐person, computer‐based and telephone‐administered cognitive assessment. Cross‐platform consistency was high for dementia screening measures and semantic fluency, underscoring the validity of remote testing approaches. Concurrent measurement of blood‐based biomarkers revealed that glial fibrillary acidic protein and phosphorylated tau-181 reliably distinguished Alzheimer’s disease from milder cognitive disorders. This work exemplifies how integrated recall studies can support harmonised data collection, validate registry diagnoses and link molecular markers with functional outcomes in routine clinical practice.

Cognitive Assessment and Functional Impairment in Dementia publication trend

The graph below shows the total number of articles in cognitive assessment and functional impairment in dementia across all publications each year (not limited to Nature Index journals).

Technical terms

Instrumental Activities of Daily Living (IADL): Complex everyday tasks such as managing finances, medication and transportation, sensitive to early functional decline.

Blood-based biomarker: A molecule measurable in blood (for example, phosphorylated tau or glial fibrillary acidic protein) that reflects underlying neuropathology.

Positron Emission Tomography (PET): A neuroimaging technique using radiotracers to visualise molecular pathology (amyloid or tau) in vivo.

Mild Cognitive Impairment (MCI): A clinical state characterised by measurable cognitive deficits not severe enough to interfere significantly with daily function.

Recall study: A research design in which participants are selected or “recalled” from a larger registry or biobank based on predefined diagnostic or genetic criteria for further detailed assessment.

References

1. Generating real‐world evidence in Alzheimer's disease: Considerations for establishing a core dataset. Alzheimer's & Dementia (2024).
2. Regional cerebral tau predicts decline in everyday functioning across the Alzheimer’s disease spectrum. Alzheimer's Research & Therapy (2023).
3. A FinnGen pilot clinical recall study for Alzheimer’s disease. Scientific Reports (2023).
4. Potential New Approaches for Diagnosis of Alzheimer's Disease and Related Dementias. Frontiers in Neurology (2020).