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Cognitive disturbance refers to temporary or chronic disruptions in thinking, memory, concentration, or decision-making. While dementia is a well-known cause, not all cognitive disturbances in older adults indicate dementia. Factors such as acute illness, medications, emotional distress, or sleep problems can also contribute. Recognising the difference between dementia and other forms of cognitive disturbance is essential for accurate diagnosis, appropriate care, and maintaining quality of life.
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Trends and statistics
Cognitive disturbances are increasingly common in older adults, especially with global ageing population. Studies show that approximately 15-20% of people aged 65 and above experience mild cognitive impairment (MCI), a condition that may not progress to dementia. Moreover, delirium affects up to 50% of hospitalised older adults, especially after surgery or severe illness. These trends highlight the importance of evaluating cognitive symptoms beyond the dementia lens.
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Types of non-dementia cognitive disturbances
There are other cognitive disturbances that are not related to dementia. These may include the following:
Delirium
A sudden, fluctuating state of confusion, often due to acute illness or medications.Mild Cognitive Impairment (MCI)
Slight but noticeable decline in cognitive abilities, not severe enough to interfere with daily life.Depression-related cognitive impairment
Often termed “pseudodementia”, where mood disorders mimic dementia-like symptoms.Medication-induced cognitive changes
Temporary fogginess or memory issues caused by certain drugs.Sleep-related cognitive issues
Poor sleep quality or disorders like sleep apnea affecting alertness and memory.
Causes of non-dementia cognitive disturbances
Cognitive disturbances may result from a wide range of non-dementia factors, such as:
Infections (e.g., urinary tract infection, pneumonia)
Medication side effects (e.g., benzodiazepines, anticholinergics)
Dehydration or poor nutrition
Vitamin deficiencies (e.g., B12, folate)
Depression and anxiety
Sleep disorders (e.g., insomnia, sleep apnea)
Substance use or withdrawal
Acute hospitalisation or surgery (especially under general anesthesia)

Signs and symptoms
While symptoms vary depending on the cause of cognitive disturbances, common signs include:
Sudden confusion or disorientation
Difficulty concentrating or focusing
Memory lapses not affecting daily functioning
Changes in alertness or awareness
Slowed thinking or speech
Mood swings or increased anxiety
Sleep disturbances
Unlike dementia, these symptoms often have a clear trigger and may improve with treatment of the underlying cause.
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Treatment options
Treatment depends on identifying and addressing the root cause:
Delirium
Requires urgent management of infection, pain, or medication adjustment.Depression or anxiety
Psychotherapy or antidepressants may help.Nutritional deficiencies
Supplementation with vitamin B12 or folate.- Medication-related issues
Switching or tapering off problematic drugs. Sleep disturbances
Sleep hygiene education or treatment of sleep apnea.Cognitive training
Tailored mental exercises to improve concentration and memory.
A multidisciplinary approach consists of general practitioner, clinical psychologist, dietitian, speech and language therapist, occupational therapist, nurse, social worker, pharmacist, etc. often yields the best outcomes.
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How you can prevent non-dementia cognitive disturbances
To prevent non-dementia cognitive disturbance while you are still healthy, be sure to consistently follow the practices outlined below:
Stay well-hydrated and maintain a balanced diet
Regularly review medications with a healthcare provider
Engage in regular physical and mental exercise
Manage chronic health conditions like diabetes or hypertension
Treat mental health issues promptly
Ensure proper sleep habits
Encourage social engagement and meaningful activities

Conclusion
Cognitive changes in older adults can be worrying, especially when they appear suddenly or begin to interfere with daily life. However, it’s important to remember that not all cognitive disturbances are signs of dementia. Many conditions such as infections, depression, medication side effects, or nutritional deficiencies can temporarily impair memory, thinking, or attention. The good news is that these non-dementia causes are often treatable or reversible, especially when identified early.
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Family members and caregivers should be cautious not to jump to conclusions. Mislabeling someone with dementia can lead to unnecessary fear, stigma, or even inappropriate care decisions. Instead, observe the symptoms carefully, look for possible triggers, and consult a healthcare professional for a proper assessment. A comprehensive medical evaluation, sometimes including blood tests, cognitive screening, or brain imaging, can help determine the root cause and the best course of action.
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Self-diagnosing or delaying medical help can worsen the condition or mask a serious underlying issue. If you are unsure whether the changes you are seeing are part of normal ageing, a temporary cognitive disturbance, or the early signs of dementia, it’s always safer to err on the side of caution.
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