Often when people learn that they or a loved one have been diagnosed with mild cognitive impairment, they assume that this means they have early-stage dementia. But is mild cognitive impairment dementia, or something else? And if they’re not the same thing, how are they different?
Clearly, these terms are closely related. Let’s look carefully at their definitions as laid out by the National Institute of Neurological Disorders and Stroke:
Notice that in the above definitions, the key differentiator between these two conditions is that in MCI, the cognitive impairment poses no significant barrier to the person’s ability to carry out everyday tasks and live independently. It is after this line has been crossed and a person’s ability to handle everyday functions has been compromised that we begin to speak in terms of dementia rather than MCI.
Note, too, that it is incorrect to assume that a person diagnosed with MCI is on the path to full-blown dementia. Two-thirds of people with MCI never develop dementia, and MCI can be caused by brain injury, drug side effects, and other things that have nothing to do with dementia.
Perhaps the best way to conceptualize the relationship between MCI and dementia is to imagine human cognition as existing along a spectrum. To the left is normal cognitive functioning. Next to it, moving to the right, is the mild memory loss that is a normal part of aging. Further to the right is MCI, followed by mild dementia, moderate dementia, and then severe dementia.
Such a model is useful as long as you bear in mind that it only represents various states of cognitive function rather than portraying a necessarily sequential progression. For example, someone with normal age-related memory loss is not on an inexorable path toward dementia, nor even toward MCI. Someone else could go directly from normal age-related memory loss to dementia without ever being diagnosed with MCI.
All of that is clear enough in an abstract sense, but in practical terms, how might daily life for someone with MCI look different from that of someone with dementia?
Let’s imagine two people, Mike and Carrie. Mike has MCI and Carrie has mild dementia.
Mike (MCI)…Mike drives himself to and from work every day. Several months ago, he missed three important meetings, so he began using his computer’s calendar app to begin notifying him two days before each appointment. He never used to be much of a note-taker, but lately has begun writing down everything said during meetings…not just so he will remember it later, but because note-taking helps keep his mind from wandering during discussions. He’s occasionally embarrassed when colleagues ask him how he spent the weekend and he’s unable to recall a single detail. Sometimes in the middle of a conversation he’ll pause, searching for a word. His friend or colleague will know what word he’s looking for and will offer it up, and he’ll often be horrified to have been unable to come up with such a simple, everyday word. He and his wife Linda have been looking forward to a European vacation in a few months, but every time he tries to plot out the complex itinerary, he gets overwhelmed by all the moving parts. For the first time in their marriage, Linda will be the one to piece the trip together. Mike is trying to work up the courage to ask her to take over handling the household finances.
Carrie (dementia)…After a few scary close calls last year, Carrie no longer drives at all. A few months ago, she moved in with her daughter and son-in-law after the family discovered that she had stopped paying her bills and was not taking care of her personal hygiene. Carrie ran track in high school and until very recently has been justifiably proud of her athleticism, but lately she’s begun to hold the railing carefully when she descends the stairs. She still remembers all her family members, but they’ve had to adjust to hearing her repeat comments and questions just a few minutes apart. She used to have trouble coming up with single words like Mike does, but now her struggles with language are broader. She sometimes becomes tongue-tied when she’s on the phone with her other children and grandchildren, finding it challenging to keep up a simple conversation. Carrie used to fill the home with puns and snippets of songs, and while she occasionally still surprises her family with a wry joke, most of the time she sits quietly in her room with the TV on. On two recent occasions when the family was getting ready to go somewhere, she made everyone late by refusing to get dressed and brush her teeth.
It’s understandable that an MCI diagnosis can be scary because of the chances that it could progress to dementia. Take those concerns to your doctor, who may be able to offer further insights regarding your prognosis. Even without the specter of dementia, having MCI represents a new set of struggles that are no fun to deal with. Speaking to a counselor or therapist with experience in this area might help you manage some of the emotional and relationship-related challenges that come with the diagnosis.
