Forgetfulness May Not Signal Dementia, Experts Say

Everyday memory lapses, such as forgetting names or misplacing keys, are frequently overinterpreted as early indicators of dementia. However, neuroscience experts suggest that these minor forgetful moments are often caused by fatigue or stress, rather than the onset of a neurodegenerative disease. True cognitive changes, if they occur, may be reversible if addressed promptly.

Dr. Tommy Wood, a professor of pediatrics and neuroscience at the University of Washington, noted that when people are stressed or tired, memory issues are typically related to retrieval—the memory exists, but accessing it is difficult. This is distinct from memory loss associated with neurodegenerative diseases, where the memory may not have been encoded in the first place.

"If you're noticing something's not quite right, that's usually a good sign," Wood stated, emphasizing that awareness of potential issues can be a positive indicator. "If you want to remember something ... you need to actually be focused, be paying attention. You need to tell your brain it's important to remember it."

Dementia is clinically defined as a loss of cognitive function severe enough to impair daily independent living. Alzheimer's disease and vascular dementia constitute the majority of cases. Research indicates that a significant portion of dementia cases could be prevented by modifying lifestyle and health risk factors. Key preventable risk factors include problems with heart and metabolic health, as well as hearing and vision loss.

Wood highlighted that addressing physical health issues, such as obtaining hearing aids or undergoing cataract surgery, can directly reduce the risk of cognitive decline. "If you expect decline, you won't do the things that will prevent decline from happening," he said. "Believing that it's possible means you'll actually engage in these processes, and then through that, you can prevent a lot of this decline."

The focus on reversible causes of cognitive symptoms aligns with guidance from medical institutions like the Mayo Clinic and Cleveland Clinic. These organizations point out that several treatable medical conditions can mimic early dementia symptoms or contribute to subjective cognitive decline. Common reversible causes include vitamin deficiencies (especially B12 and B1), thyroid problems (like hypothyroidism), medication side effects, mental health conditions such as depression and severe anxiety, and metabolic or kidney issues.

Cleveland Clinic emphasizes that early clinical intervention is critical when individuals notice changes in "brain fog" or executive function. "How your brain functions on a day-to-day basis is kind of the output of everything your brain is dealing with," Wood explained. "But if you start to notice something, there's still time to make some changes if you need to."