Dementia is not a specific disease. Instead, it is rather a general term for the impaired ability to remember, think, or make decisions that interferes with everyday activities. Alzheimer’s disease is the most common type of dementia. Although dementia mostly affects older adults, it is not a part of normal ageing.¹

Isn’t dementia part of normal ageing?

In the journey of ageing, it is natural to wonder about the changes that come with time. One common question that often arises is whether dementia is just a normal part of getting older. The truth is, while ageing does bring about its own set of transformations, dementia is not a typical feature of this process.

Think of it this way: many older adults navigate through life without ever experiencing dementia. Ageing might bring about changes like muscles that aren't as strong as they used to be, arteries that might stiffen up a bit, and some minor hiccups in memory. You may forget the name of a distant acquaintance or have a little trouble keeping track of the most recent events.

But here's the important part. While these small memory blips might happen, the core of who you are – your wealth of knowledge, your cherished experiences, and your ability to communicate – typically stays strong. Your old memories remain intact, and you are still able to express yourself fluently.¹

What increases the risk for dementia?

These are factors that can pose more risk of getting dementia, but they are not medically inclined.

1. Age: The primary risk factor for dementia is age, particularly over the age of 65
2. Family History: A family history of dementia significantly raises one's risk
3. Race/Ethnicity: African American and Hispanic people face higher dementia risks than white people
4. Heart Health: Conditions affecting the heart like high blood pressure and smoking can increase dementia risk
5. Traumatic Brain Injury (TBI): Serious or repeated head injuries can greatly increase the likelihood of developing dementia later in life

What are the most common types of dementia?

1. Alzheimer’s Disease: This is the leading type of dementia, making up 60 to 80% of cases. It starts with having difficulty remembering recent conversations. It then progresses to more severe memory loss and changes in personality. If a close family member has Alzheimer’s, your  risk of developing it increases by 10 to 30%
2. Vascular Dementia: About 10% of dementia cases occur after strokes or problems with the blood flow in the brain. Symptoms can vary but worsen suddenly following further strokes. High blood pressure, diabetes, and high cholesterol also contribute to the risk of developing this type of dementia
3. Lewy Body Dementia: Beyond memory loss, this type of dementia can involve physical symptoms like stiffness and tremors. It can also cause drowsiness, confusion during the day, and visual hallucinations
4. Fronto-Temporal Dementia: This affects personality and behaviour because it impacts specific areas of the brain. Those with the condition may act in an unusual manner. Examples of this are making offensive comments or neglecting daily responsibilities. Language difficulties are also common
5. Mixed Dementia: This refers to having more than one type of dementia simultaneously. This is typically seen in older adults. It can be hard to diagnose because the symptoms of the different dementias might overlap. This overlap makes the condition more severe
6. Reversible Causes: In some cases, dementia symptoms are caused by reversible issues. These can include medication side effects, increased brain pressure, vitamin deficiencies, or thyroid problems

The protective role of the immune system in our brain

Alzheimer's disease occurs when the brain's immune system fails to function properly. This error can result in more brain injury. 

Our immune system is essential for keeping our brain healthy. It helps control inflammation and fights off infections. Special cells called microglia, which live right in the brain, play a key role. They keep the brain environment stable and support the creation of new brain cells.²

The microglia cells that typically protect the brain fail to activate appropriately. This results in an imbalance of damaging and protective messages in the brain. This imbalance may accelerate the progression of dementia.³

The link between inflammation and dementia

Long-term inflammation in the brain can destroy neurons. Neurons (nerve cells) transfer information throughout the brain and body. This inflammation alters how neurons function and contributes to their deterioration. This can accelerate symptoms associated with dementia, such as memory loss and disorientation.¹⁰

The new frontier: immunotherapy’s role in conquering dementia

Current treatments in immunotherapy

Vaccines designed for dementia

Researchers are creating vaccinations specifically to combat dementia. These vaccines target toxic proteins including amyloid-beta and tau. Both of the proteins are strongly associated with Alzheimer's disease. By engaging the body's own immune system to combat these proteins, vaccinations could potentially halt the advancement of dementia.⁵

Antibody therapies

Antibody treatments employ specially designed molecules to target and neutralise proteins that accumulate in Alzheimer's disease. These proteins are called amyloid-beta and tau. Antibody treatments have shown potential in clinical trials. There, they helped to lower these toxic proteins and ease the symptoms linked with dementia.⁶

Experimental approaches

Cell-based therapies

Innovative cell-based therapeutics are being developed. They are designed to either control the immune system or replace damaged neurons. Although still in the research phase, these medicines may one day provide new strategies to treat dementia. These cell-based therapies target the underlying causes of immunological and cellular dysfunction.⁷

Potential of immunomodulators

Immunomodulators are medications designed to modify the immune system's response to neurodegeneration. Neurodegeneration is the process that causes illnesses such as dementia.⁸

These medicines are meant to alter how the brain's immune cells respond to disease. This will ideally minimise inflammation and its negative consequences. Researchers are actively investigating these medications to better understand their benefits and hazards in treating dementia.

Challenges in immunotherapy for dementia

Navigating the complexity of brain treatments

When creating Alzheimer's disease treatments, it is critical that they are exceedingly accurate. This precision is required because the medication may target healthy brain cells as well as toxic proteins. This may induce inflammation or neuronal damage. Getting this right is difficult and necessary to prevent worsening an already difficult situation.

Concerns over safety and side effects

There are certain concerns when using immunotherapy to treat dementia. For example, the AN-1792 experiment had to be stopped due to serious side effects, including brain inflammation. Now, the emphasis is on making these medicines safer by targeting only the damaging regions of proteins. Doing so lowers the possibility of unexpected consequences such as autoimmune responses.⁹

The promise of tomorrow: a world beyond dementia

Immunotherapy is quickly becoming a hopeful strategy for potentially transforming the methods that we treat dementia. This is especially true for Alzheimer's disease. Immunotherapy uses techniques that actively and passively remove harmful proteins such as amyloid-beta and tau from the brain. These proteins are known to play a big part in advancing the disease. Early trials have faced some challenges, like side effects related to the immune system. Nevertheless, these trials are essential for developing safer and more effective treatments. The progress made could mean more than just easing symptoms it might actually change the course of the disease itself.

Looking ahead, the future of dementia research and treatments is exciting. There is a lot of optimism around new therapies. One example is the use of monoclonal antibodies tailored to target specific versions of the amyloid-beta protein. These antibodies are being crafted to be more effective and safer. This is done by making these antibodies focus on certain forms of the protein. There is also promising work on treatments aimed at the tau protein. This could be especially beneficial in the later stages of Alzheimer's and other similar disorders. Moreover, researchers are working on therapies that address several aspects of the disease at once. This approach has the potential to offer more extensive benefits.

Summary

Dementia impairs a person’s ability to think, remember and make decisions. It is not a natural part of ageing. Certain factors are known to increase the risk of developing dementia. These include being above a certain age or having a family history of dementia. Common types of dementia are Alzheimer’s disease and vascular dementia. Out-of-control inflammation affecting nerve cells is the primary cause of dementia. This type of unchecked inflammation is brought on by a malfunctioning immune system and the presence of certain harmful proteins. The buildup of proteins like amyloid-beta and tau have been linked to the appearance of Alzheimer’s disease. Current dementia therapies hinge on targeting such dangerous proteins using vaccines or antibodies. Potential future therapies aim to control the immune system to reduce inflammation and/or replace damaged nerve cells. While these new therapy options are promising, it is imperative that they are thoroughly refined and tested. This needs to be done to ensure maximal benefit and minimal side effects.