What is the difference between subjective cognitive decline, mild cognitive decline and mild Alzheimer's? 

 

These three terms often get used together, but they mean different things along the spectrum from normal aging to Alzheimer’s disease. Here’s a clear breakdown:

 

1. SCI (Subjective Cognitive Impairment / Subjective Cognitive Decline)

What it means:

A person notices problems with memory or thinking, but when tested, their scores are still in the normal range for their age.

 

Examples:

Misplacing things more often, feeling like names or words are harder to recall, needing more effort to concentrate.

 

Testing:

No objective evidence of impairment on cognitive testing.

 

Daily life:

No impact on independence.

 

Important note:

SCI can be a “warning stage,” as some people with SCI later develop MCI or dementia, but not everyone does.

 

 

2. MCI (Mild Cognitive Impairment)

What it means:

A step beyond SCI. There is measurable evidence of memory or thinking problems on testing, greater than expected for normal aging.

 

Examples:

Forgetting important appointments, repeating questions, taking longer to make decisions, trouble following conversations.

 

Testing:

Cognitive tests show mild deficits, usually in memory, attention, or language.

 

Daily life:

Person remains independent in everyday activities (cooking, finances, self-care), though tasks may take longer or need compensatory strategies (notes, reminders).

 

Progression:

About 10–15% of people with MCI progress to Alzheimer’s each year, though some remain stable or even improve.

 

 

3. Mild Alzheimer’s Disease (Early Dementia Stage)

 

What it means:

Memory and thinking problems are significant enough to interfere with daily life and independence.

 

Examples:

Frequently forgetting recent events, difficulty managing finances or medications, repeating the same stories, getting lost in familiar places, personality or mood changes.

 

Testing:

Clear evidence of impairment across multiple cognitive domains.

 

Daily life:

Independence starts to be compromised. The person may still live at home but often needs help with complex tasks (bill paying, driving, cooking).

 

Medical diagnosis:

At this stage, doctors can confidently diagnose Alzheimer’s dementia (mild stage).

 

 

In short:

SCI: "I feel my memory is slipping" — but tests are normal, and daily function is fine.

 

MCI: "My memory is measurably worse than normal aging" — but daily independence is intact.

 

Mild Alzheimer’s: "My memory/thinking problems are interfering with daily life" — dementia is present.