Mild Cognitive Impairment (MCI)

Mild cognitive impairment (MCI) is a clinical designation for cognitive decline that is measurably greater than expected for a person's age and education level, but not severe enough to significantly interfere with daily activities. It occupies the territory between normal aging and dementia.

MCI can affect memory primarily (amnestic MCI) or other cognitive domains such as language, attention, or visuospatial ability (non-amnestic MCI). Amnestic MCI — where memory is the primary affected domain — is the most common type and carries the highest risk of conversion to Alzheimer's disease.

MCI is not a single entity. It is better understood as a heterogeneous condition with multiple possible causes, multiple possible trajectories, and no single biological fingerprint. Some people with MCI progress to dementia. Others remain stable for years. A meaningful minority improve over time, particularly when MCI was caused by treatable conditions like depression, thyroid dysfunction, or medication side effects.

MCI is clinically significant because it identifies people at elevated risk for progression to dementia. Approximately 10-15% of people with MCI convert to Alzheimer's disease each year, compared to 1-2% of the general older adult population. Over five years, roughly 40-50% of people with amnestic MCI will progress to dementia — predominantly Alzheimer's disease.

The MCI stage is also the window in which emerging disease-modifying treatments are most likely to be effective. Anti-amyloid antibodies like lecanemab and donanemab are approved specifically for early Alzheimer's disease, which includes the MCI due to Alzheimer's stage. Identifying MCI before progression to dementia is therefore increasingly clinically actionable.

Diagnosis of MCI requires clinical evaluation by a healthcare provider. Self-reported cognitive concerns alone are not sufficient to diagnose MCI, though subjective cognitive decline — noticing more difficulty than usual with memory or thinking — is a legitimate reason to seek evaluation.

Keel is not a diagnostic tool and cannot diagnose MCI. What Keel can do is provide longitudinal data about the cognitive domains — processing speed, working memory, spatial reasoning, semantic fluency, and reaction time — that are relevant to early cognitive change. A sustained decline across multiple domains over weeks and months is meaningful data worth bringing to a healthcare provider for professional evaluation.

Tracking your cognitive baseline over time with Keel also provides context that a single clinical assessment cannot: it separates a bad day from a real trend, and it can document the trajectory of change that helps clinicians distinguish MCI from normal variation.