Definitions:
COGNITION = the ability to form, process and understand thoughts
MCI = mild cognitive impairment
D = dementia
AD = Alzheimer’s disease
This newsletter will primarily focus on the changes in cognition that occur with aging, and not those affiliated with brain trauma or disease.
What is “Normal” Cognitive Decline
How do we know if our “forgetfulness” is normal or on a path to Dementia? If what is being experienced doesn’t interfere with daily life, and normal independent functioning/activity are continued, then this is appropriate age-related cognitive decline. Examples include: forgetting where things are put, taking longer to learn new tasks, occasionally struggling to find the right word or name in conversations, trouble focusing in conversations when there is distraction.
With increasing age, some decrease in cognitive functioning is expected; functions that depend on processing speed, attention, working memory, verbal recall and executive function all decline, with variation from person to person, whereas vocabulary and general knowledge of world events tend to be retained. It is important to note that simple forgetfulness is not the same as cognitive decline. Think of cognitive decline as a sequence or progression of symptoms that at any point can stabilize, slow or continue to decline.
Some examples of MCI are:
- Trouble finding the right words
- Frequently losing/misplacing things
- Forgetting appointments/scheduled events
- Becoming overwhelmed by complex tasks/projects
It should be emphasized that all MCI does not lead to dementia, it is just one of many risk factors. And it is a point in time when evaluation by a doctor should probably be initiated.
The changes that come with aging are related to anatomical changes in the white matter of the brain, decreased integrity and size of certain nerve pathways. What we want to distinguish here is the difference between normal cognitive decline vs. a disorder, which is dementia, that interferes with daily life.
Occasionally, improved cognitive function is seen with aging; there is evidence for this on brain scans which show intact neuroanatomical structures and connections. These viable nerve pathways can be maintained via responses to mental challenges. This illustrates the importance of early diagnosis in people with MCI because of the potential for the brain to retrain and remodel itself as a means of compensation for deterioration.
This is fascinating, as it suggests a certain plasticity, or flexibility of brain function, and the existence of so-called cognitive reserve, like a savings account or back-up hard drive, but in the form of neurons, available to be recruited when certain areas are not working well/starting to weaken. How is this backup pulled up? Cognitive training enhanced with aerobic exercise and mental exercises (ie, games, new language learning) are some strategies that have been shown to be effective in this area.
Some health conditions can lead to the decreased thinking and memory that come with ageing. High blood pressure, vascular disease (like a previous stroke), depression, sleep deprivation, hearing loss and diabetes are some examples. Nutrition, diet, exercise and genetics are also factors that can affect the propensity for cognitive decline, as well as education level, accumulated stress, race and social connections later in life.
Where Does Senility Fit In
The word “senile” is an older term that referred to the symptoms of dementia that developed after age 65, and pre-senile dementia for a while referred to Alzheimers disease. Today the term has become obsolete, due to its negative connotation and inaccuracy, and is replaced with early-onset (prior to age 65) and late-onset dementia.
When Should I Be Worried or See a Doctor
Getting lost in places that were once familiar, asking the same questions repeatedly, communication frustrations and trouble recognizing friends and family are some strong clues. Changes in mood and personality may be associated as well. There are many neurocognitive screening tests available to check the likelihood of cognitive decline or MCI; a common one your doctor may have you download at home is a self-test called the SAGE test. These tests are not absolute but can be a guide for your doctor on how best to proceed in making a diagnosis. Brain scans, lumbar puncture and labs are also part of the workup. Again, early diagnosis is very important to slowing the progression of D, and even reversing disease if an underlying treatable condition is found.
Some Common Types of Dementia
- Alzheimer’s Disease is the most common type and is characterized by tau proteins built up in the brain leading to memory and cognitive decline
- Vascular Dementia is caused by damaged blood vessels in the brain leading to decreased oxygenation of nerves
- Lewy Body Dementia is also caused by abnormal protein deposits leading to memory loss, hallucinations and movement disorders
- Frontotemporal Dementia elicits personality, behavioral and language deterioration, and often occurs prior to age 65
Treatment Options
AD and other dementias are still only partially understood by experts. While there is no cure, there are medications to help improve symptoms and slow the progression. Medications like ARICEPT (a cholinesterase inhibitor) can help with some of the symptoms by making brain-friendly chemicals more available in brain neurons and pathways, especially those related to memory. As the disease progresses, its effectiveness decreases, so it is used in earlier AD stages. NAMEDA (an MNDA antagonist) can help in the later stages by protecting brain cells from deterioration. There are also medications to help with associated symptoms such as anxiety, depression, aggression, insomnia and psychosis, but only on a short-term basis due to exacerbating side effects. Note that all classes of medications carry risk of side effects which may affect the ability to tolerate therapy. Your doctor will discuss and guide you through these options.
How to Prevent or Delay Cognitive Decline
While there is not much to be done to change the genetic risk of dementia, there are several steps to take to help preserve brain health and the ability to think. These tips are grounded in research:
- eat a nutritious diet rich in green leafy vegetables
- maintain a healthy and recommended blood pressure
- be and stay physically active
- maintain social connections
- engage with brain-stimulating activities like games, books and hobbies
- protect your brain with sports helmets and seat belt use
- limit or avoid alcohol and tobacco, fried foods, sugary foods and drinks
References:
Healthline Cognitive Decline 2024
PMC/NIH Overview of Neurocognitive Disorders 2017
VeryWellmind Alzheimer’s Disease Feb 2026
Psychology Today Memory Loss or Dementia March 2025