Mild Cognitive Impairment & Dementia

Both "mild cognitive impairment (MCI)" and "dementia" are not diagnoses, but rather represent "stages" of severity of a disease. There are many diseases that can lead to MCI, and later, dementia, including Alzheimer's disease (AD), stroke, Parkinson's disease, Frontal lobe disease, head trauma, certain vitamin deficiencies, hormone deficiencies, other common medical conditions, and depression. Therefore, it is very important to identify what is causing MCI or dementia in order to define the right treatment. In AD, the average duration of symptoms is 14 years, of which MCI lasts about 7 years and dementia lasts about 7 years.

Mild Cognitive Impairment

The MCI severity stage precedes the dementia stage. During MCI, skills that place greater demands on your cognitive abilities may begin to decline. Some examples include learning new skills for your work or hobby, managing complex tasks, reading several books at a time and keeping track of the stories, remembering recent conversations or recent events, keeping track of upcoming appointments, and traveling to new locations. In AD, the average duration of the MCI stage is about 7 years. However, the memory loss during the first 3-5 years of the MCI stage can be so subtle that it may be interpreted as due to aging. This is why annual memory checkups after 50 years old are so important.


The definition of dementia has two parts. The first part requires that you have developed difficulties in two or more cognitive abilities including:

  • Remembering recently learned information
  • Recognizing and naming objects, such as people or other familiar things
  • Communicating to others as well as understanding what they communicate to you
  • Making decisions or judgments about things that are personally important
  • Planning, organizing and executing simple and complex tasks

The second part requires that these "cognitive difficulties" affect the ability to perform your usual social and daily routines of life, such as driving, preparing a meal, shopping for groceries, doing household chores, managing finances, or paying bills.

Dementia is further classified into mild, moderate, and severe dementia stages. Although different diseases decline at different rates, in the case of AD, it takes an average of 7 years to progress from mild to severe dementia if not treated. However, current treatment of AD can delay its procession by 50% or more.