From the Guidelines
Diagnosing dementia requires meeting specific clinical criteria that focus on cognitive decline, as outlined in the most recent guidelines from the Alzheimer's Association, which emphasize a comprehensive evaluation including medical history, cognitive assessments, laboratory tests, and often brain imaging 1.
Key Diagnostic Criteria
The diagnostic criteria for dementia include:
- Significant impairment in at least two cognitive domains, such as memory, language, executive function, attention, visuospatial skills, or social cognition, that represents a decline from previous functioning.
- Deficits that are severe enough to interfere with daily activities and independence, distinguishing dementia from normal aging.
- Cognitive changes that cannot be explained solely by delirium or another mental disorder.
Comprehensive Evaluation
A comprehensive evaluation for diagnosing dementia typically involves:
- Medical history
- Cognitive assessments, such as the Mini-Mental State Examination or Montreal Cognitive Assessment
- Laboratory tests to rule out reversible causes
- Often, brain imaging
Importance of Progressive Decline
The cognitive decline must be progressive over time, which helps differentiate dementia from static cognitive impairments.
Behavioral and Psychological Symptoms
The diagnostic process should also include assessment for behavioral and psychological symptoms that often accompany dementia, such as mood changes, agitation, or hallucinations.
Recent Guidelines
The most recent guidelines from the Alzheimer's Association, published in 2025, provide a structured approach for evaluating patients with symptoms that may represent clinical Alzheimer's disease or related dementias 1. These guidelines emphasize the use of validated clinical assessment instruments to measure symptoms in daily life and to test for signs of cognitive impairment in the office.
From the Research
Diagnostic Criteria for Dementia
The diagnostic criteria for dementia involve a comprehensive evaluation of a patient's cognitive and functional abilities, including:
- A thorough medical history and physical examination to identify potential underlying causes of cognitive decline 2, 3, 4, 5, 6
- Corroboration from a close friend or family member to evaluate cognitive decline and impairment in daily activities 2
- A mental status examination by a clinician to delineate impairments in memory, language, attention, visuospatial cognition, executive function, and mood 2, 4
- Brief cognitive impairment screening questionnaires to initiate and organize the cognitive assessment 2, 3, 6
- Neuropsychological testing to determine whether dementia is present if the assessment is inconclusive 2, 3, 4
- Physical examination to identify the etiology of dementia, such as focal neurologic abnormalities suggesting stroke 2, 6
- Brain neuroimaging to demonstrate structural changes, including focal atrophy, infarcts, and tumor 2, 3, 4
- Additional evaluation with cerebrospinal fluid assays or genetic testing in atypical dementia cases 2, 4
Clinical Diagnostic Criteria
Clinical diagnostic criteria for dementia include:
- A standard diagnostic evaluation that can be performed by family physicians over multiple visits, involving a clinical history, physical examination, and brief cognitive testing 3
- A list of core laboratory tests to rule out treatable causes of dementia or to rule in cerebrovascular disease 3
- Structural imaging with computed tomography or magnetic resonance imaging in selected cases 3, 4
- Proposed new diagnostic criteria for Alzheimer disease that recognize nonamnestic presentations and assign greater likelihood to diagnosis if progressive cognitive decline is documented or if biomarkers are supportive 4
Diagnostic Evaluation
A diagnostic evaluation for dementia should include:
- A comprehensive evaluation of patient cognitive and functional abilities, diagnostic laboratory evaluation, and brain imaging 5
- Validated cognitive assessment tools to identify the extent and nature of cognitive deficits and track disease progression over time 5
- Advances in the field of dementia research, such as serum biomarkers, to facilitate an earlier and more accurate diagnosis 5
- The use of telemedicine for dementia diagnosis, which can expand access to care for individuals in remote or underserved areas 5