Around the world, millions of people are living with Alzheimer’s disease—a debilitating brain disorder that progressively destroys memory and cognitive abilities.
Despite decades of research and hundreds of clinical trials, there is still no effective way to prevent or cure Alzheimer’s. Why is it so challenging to treat?
Symptoms of Alzheimer’s Begin Early and Progress Silently
Alzheimer’s accounts for 60 to 80% of all global dementia cases. Dementia is an umbrella term used to describe various conditions that affect memory, thinking skills, and daily functioning.
Most Alzheimer’s patients first notice symptoms in their 60s, often with mild memory issues such as forgetting dates or recently learned information. Some also experience mood swings, increased anxiety, agitation, and difficulty adapting to new situations.
These symptoms typically worsen over years, and eventually, people with Alzheimer’s may require constant care. While rare cases of Alzheimer’s are linked to genetic mutations, most cases result from a complex interplay of genetic, lifestyle, and environmental factors, making it difficult to predict who is at risk.
Alzheimer’s progresses over a long, chronic course, often starting one to two decades before symptoms appear. During this time, the brain undergoes gradual but significant changes.
Why Is Alzheimer’s So Hard to Treat?
Initially, scientists discovered abnormal buildups of a compound called beta-amyloid in the brains of Alzheimer’s patients. Beta-amyloid is formed when a larger protein, amyloid-beta precursor protein (APP), is broken down. However, in Alzheimer’s, APP may be improperly cleaved, producing sticky beta-amyloid plaques that accumulate between neurons, disrupting normal signaling. Interestingly, not everyone with these plaques develops dementia, and Alzheimer’s symptoms don’t always worsen as plaques build up.
In the 1980s, another protein called tau emerged as a potential culprit. Normally, tau helps stabilize the internal structure of neurons. But in Alzheimer’s, tau becomes misfolded and clumps together, forming tangles inside neurons. These tangles are toxic, eventually leading to neuron death.
Recent studies also implicate changes in immune cells called microglia, which protect the brain, in the disease’s progression. Alterations at synapses (connections between neurons) and disruptions in brain energy metabolism may also contribute. This complexity suggests that Alzheimer’s likely results from a cascade of interrelated events, making it difficult to identify and interrupt the process at its root.
Managing Symptoms and Promising Research
While the complexity of Alzheimer’s makes it difficult to cure, some strategies can help manage symptoms. Staying mentally and physically active, learning new skills, and engaging in daily activities can improve quality of life. Certain medications that target neurotransmitters may slow memory loss and enhance learning.
Emerging therapies, such as drugs targeting beta-amyloid, show promise in slowing disease progression and reducing plaque accumulation in the brain.
With cases of Alzheimer’s and dementia expected to double in the next 20 years, research efforts are intensifying. While challenges remain, scientists are making progress toward understanding and eventually overcoming this devastating disease.