Alzheimer’s Breakthrough: What’s Forgotten First Before Diagnosis?

MEXICO CITY (apro).— Alzheimer’s disease leads to a progressive decline in cognitive function, with scientific studies agreeing that episodic memory is usually the first to be affected. This refers to the ability to recall personally experienced recent events.

What is Episodic Memory and Why is it Primarily Affected?

Episodic memory encompasses the system that stores memories of personal situations or experiences within a specific time and space context, like “I went to the market yesterday” or “I had a meeting this morning.” Research from the National Institutes of Health (NIH) and the Journal Neurobiology of Aging indicate that disruptions in this function are among the earliest significant signs of Alzheimer’s.

Additionally, the National Center for Biotechnology Information (NCBI) has documented that both working memory and long-term declarative memory begin to deteriorate in the early stages of the disease.

How Does This Early Forgetfulness Manifest in Daily Life?

Initial symptoms may include:

• Forgetting recent conversations or events that just happened.
• Misplacing items and being unable to recall where they were left.
• Struggling to follow new instructions or learn new information.

According to the Alzheimer’s Association and the Mayo Clinic, these symptoms are explained by the so-called Ribot’s Law, which states that the most recent memories are more vulnerable to neurological deterioration than older ones.

Why Does This Pattern of Forgetfulness Occur?

This type of forgetfulness arises from damage to brain structures involved in forming new memories, such as the hippocampus and the entorhinal and parahippocampal regions.

Reports from the National Institute on Aging in the United States explain that the accumulation of beta-amyloid plaques and tau protein tangles damages the neural networks responsible for episodic memory, causing individuals to have difficulties in recording and retrieving recent memories before other cognitive functions are affected.

What Do Recent Studies Say?

A scientific review published in the journal ScienceDirect in 2015 claims that episodic memory is the most sensitive to aging and the first to deteriorate during the course of Alzheimer’s.

Similarly, a 2025 report by the National Institutes of Health on dementia states that the disease gradually destroys memory, thinking, and reasoning abilities, with the loss of recent memories being one of the first detectable signs.

Alzheimer’s: Early Warning Signs Not to Be Ignored

• Forgetting information that was just learned or asking the same questions repeatedly.
• Relying on notes or reminders for tasks previously done from memory.
• Difficulty keeping up with recent events, appointments, or commitments.
• Confusion about the sequence of dates or familiar places.
• Disorientation when performing new or unusual tasks.

The Alzheimer’s Association recommends paying attention to these signs, as they may facilitate early detection and allow for more timely intervention or treatment strategies.

Does This Mean Only Recent Memories Are Forgotten?

Not entirely. While newer memories are the first affected, as the disease progresses, older memories may also deteriorate. However, the loss of recent memory or difficulty incorporating new information is the primary pattern identifiable in most cases.

Relevance for Early Diagnosis

Detecting changes in episodic memory is key to identifying Alzheimer’s at early stages. Institutions like the Mayo Clinic and NIH indicate that forgetting newly learned information or recent conversations is one of the first indicators that specialists should evaluate.

Key Information About Alzheimer’s You Should Know

• Loss of episodic memory is the first sign of the disease.
• Damage begins in the hippocampus, a crucial area for forming new memories.
• Detecting frequent recent forgetfulness can favor an early diagnosis.
• Beta-amyloid plaques and tau proteins are the main causes of neuronal damage.
• Remote memory (older memories) tends to be preserved in the early stages.