Major Neurocognitive Disorder (Dementia)

Major neurocognitive disorder, commonly known as dementia, is a decline in one or more cognitive abilities — most often memory, but also language, attention, planning or visuospatial skills — significant enough to interfere with independence in daily activities such as managing money, medications or household tasks. It is not a single disease but a clinical syndrome with several possible underlying causes, the most common being Alzheimer's disease, followed by vascular, Lewy body and frontotemporal causes, and mixed presentations combining more than one. Dementia is not a normal part of ageing, and while it is more common in older adults, forgetfulness alone is not the same as dementia — a proper assessment distinguishes normal age-related change, mild cognitive impairment, and dementia, because the treatment, prognosis and family planning differ substantially between them. Families in Nepal frequently delay assessment, attributing early changes to normal old age or assuming nothing can be done, when in fact earlier diagnosis allows more treatable causes to be identified, medication to be started when appropriate, and practical safety and legal planning to happen while the person can still take part in decisions.

Major neurocognitive disorder is defined by evidence of significant cognitive decline from a previous level of performance in one or more cognitive domains, based on both the person's or a reliable informant's concern and objective assessment, where the deficits are severe enough to interfere with independence in everyday activities. This distinguishes it from mild neurocognitive disorder (mild cognitive impairment), where decline is present but independence is largely preserved, and from normal ageing, where occasional forgetfulness does not affect daily functioning.

Alzheimer's disease, the most common cause, involves progressive accumulation of amyloid plaques and tau tangles leading to neuronal loss, typically starting in memory-related structures before spreading. Vascular dementia results from cumulative damage from strokes or chronic small-vessel disease, often producing a stepwise rather than smoothly progressive decline, and shares risk factors with cardiovascular disease. Lewy body dementia involves abnormal protein deposits linked to fluctuating cognition, visual hallucinations and parkinsonism. Frontotemporal dementia, which can begin at a younger age, primarily affects personality, behaviour or language before memory. A minority of cases have a reversible or partly reversible contributing cause — including thyroid disease, vitamin B12 deficiency, depression mimicking dementia (sometimes called pseudodementia), medication side effects, or normal-pressure hydrocephalus — which is exactly why a proper medical work-up matters before assuming a diagnosis is fixed and untreatable.

• Increasing age, the single strongest risk factor
• Family history of dementia, particularly early-onset cases
• Cardiovascular risk factors: hypertension, diabetes, high cholesterol, obesity and smoking
• Low levels of formal education and limited cognitive or social engagement across life
• History of stroke or significant head injury
• Untreated hearing loss, which is an increasingly recognised modifiable risk factor
• Chronic heavy alcohol use
• Social isolation and untreated depression in later life

In Alzheimer's disease, extracellular amyloid-beta plaques and intracellular tau neurofibrillary tangles disrupt neuronal communication and eventually cause cell death, with early involvement of the hippocampus and entorhinal cortex explaining the prominent early memory impairment, before spreading to other cortical regions. Cholinergic neurons, important for memory and attention, are disproportionately affected early on, which is the rationale for cholinesterase inhibitor medications. In vascular dementia, cumulative ischaemic injury disrupts white-matter connections between brain regions, often producing more prominent slowing of processing speed and executive dysfunction than pure memory loss. Regardless of the underlying cause, progressive neuronal loss reduces the brain's cognitive reserve, and factors that support brain health across life — cardiovascular fitness, cognitive engagement, and treatment of hearing loss and depression — are thought to build reserve that can delay the clinical onset of symptoms even when underlying pathology is present.

• Progressive memory loss that disrupts daily life, particularly for recent events
• Difficulty planning, organising or solving problems, such as managing bills or medications
• Getting confused about time, dates or familiar places
• Difficulty finding the right words or following conversations
• Misplacing items and being unable to retrace steps to find them
• Withdrawal from work, social activities or hobbies previously enjoyed
• Changes in mood, personality or judgment, including new suspiciousness or apathy
• Difficulty recognising familiar faces or navigating familiar routes in later stages
• Repeating questions or stories without awareness of having asked or told them already

• Evidence of significant cognitive decline from a previous level in one or more domains (learning and memory, language, executive function, complex attention, perceptual-motor, or social cognition)
• The cognitive deficits interfere with independence in everyday activities (at minimum requiring assistance with complex tasks such as finances or medication management)
• The deficits do not occur exclusively during an episode of delirium
• The deficits are not better explained by another mental disorder such as major depressive disorder or schizophrenia
• Decline is confirmed by both a concerned informant history and standardised cognitive testing wherever possible, rather than by memory complaints alone

Conditions a psychiatrist will consider and rule out before confirming this diagnosis:

Mild neurocognitive disorder (MCI)

Cognitive decline is present but independence in daily activities is largely preserved; an important distinction because MCI carries a different prognosis and monitoring plan.

Delirium

An acute, fluctuating disturbance of attention and consciousness, often with a clear medical trigger such as infection; must always be excluded or treated before a dementia diagnosis is confirmed, since delirium can be superimposed on existing dementia.

Depression (pseudodementia)

Depression in older adults can present with prominent memory and concentration complaints that improve substantially with treatment of the mood disorder, unlike true neurodegenerative decline.

Normal age-related cognitive change

Occasional forgetfulness (misplacing keys, momentarily forgetting a name) without functional impact is a normal part of ageing, not dementia.

Reversible medical causes

Hypothyroidism, vitamin B12 deficiency, medication side effects and normal-pressure hydrocephalus can all produce dementia-like pictures that partly or fully improve with treatment of the underlying cause.

• Detailed history from both the patient and a close informant, since insight is often reduced
• Standardised cognitive screening (such as the MMSE or MoCA) and, where available, fuller neuropsychological testing
• Physical and neurological examination
• Blood tests to exclude reversible contributors: thyroid function, vitamin B12, folate, and metabolic and liver function panels
• Brain imaging (CT or MRI) to assess for stroke, tumour, hydrocephalus or patterns suggestive of a specific dementia subtype
• Assessment for depression, delirium and medication effects as contributing or confounding factors
• Functional assessment of activities of daily living to establish severity and care needs

Treatment begins with identifying and addressing any reversible contributors, then focuses on slowing symptom progression where medication is appropriate, managing behavioural and psychological symptoms, and — just as importantly — structured support for the person and family to maintain safety, dignity and quality of life. There is currently no cure for the neurodegenerative dementias, so treatment goals are realistically framed around function, comfort and safety rather than reversal, and this framing is discussed openly and compassionately with the family from the outset. A care plan typically combines medication where indicated, structured daily routines, environmental adaptations for safety, and family psychoeducation, with periodic review as needs change over time.

Cholinesterase inhibitors (donepezil, rivastigmine, galantamine)

First-line for mild-to-moderate Alzheimer's disease and often used in Lewy body and Parkinson's disease dementia; can modestly slow symptom progression, with gastrointestinal side effects being the most common limiting factor.

Memantine

Used for moderate-to-severe Alzheimer's disease, sometimes combined with a cholinesterase inhibitor; works through a different mechanism (NMDA receptor modulation) and is generally well tolerated.

Cautious, targeted use of antidepressants or low-dose antipsychotics

Considered only for specific, distressing behavioural or psychological symptoms (such as significant agitation, depression or psychosis) after non-drug approaches, given the higher sensitivity to side effects and safety considerations in this population — always individualised and reviewed regularly by a psychiatrist.

Cognitive stimulation therapy

Structured group or individual activities designed to actively engage thinking, memory and language, with evidence for modest cognitive and quality-of-life benefit in mild-to-moderate dementia.

Behavioural strategies for distressing symptoms

Identifying specific triggers for agitation, wandering or resistance to care, and adjusting routines, communication style or environment accordingly, is usually more effective and safer than medication alone.

Family and carer support and psychoeducation

Structured education and emotional support for family caregivers, who carry most of the day-to-day burden in Nepal, meaningfully improves both caregiver wellbeing and the quality of care the person with dementia receives.

• Keep a consistent daily routine, since predictability reduces confusion and distress
• Maintain physical activity appropriate to ability, which supports both cognitive and cardiovascular health
• Ensure good sleep, hydration and nutrition, and review medications that can worsen confusion
• Simplify the home environment: reduce clutter, ensure good lighting, and add safety measures such as stove and door safeguards where needed
• Encourage social contact and meaningful, achievable activities rather than withdrawal
• Use memory aids — calendars, labelled rooms, written routines — while independence allows
• Treat hearing and vision problems promptly, since uncorrected sensory loss worsens confusion and social withdrawal
• Address caregiver wellbeing directly; caregiver burnout is common and affects the quality of care provided

The course depends on the underlying cause: Alzheimer's disease and most neurodegenerative dementias progress gradually over years, vascular dementia can progress in a stepwise pattern linked to further vascular events, and dementias with a reversible or partly reversible contributor (such as thyroid disease or B12 deficiency) may improve significantly once that cause is treated. Earlier diagnosis allows medication to be started when it is likely to help most, gives the person a chance to participate in decisions about future care and legal or financial planning while capacity allows, and gives the family time to plan and access support rather than reacting in crisis. While cognitive decline in the neurodegenerative dementias cannot currently be reversed, quality of life, safety and family coping can be meaningfully improved with a structured, ongoing care plan.

• Manage cardiovascular risk factors — blood pressure, blood sugar, cholesterol and weight — across mid-life
• Stay physically active and cognitively and socially engaged throughout adulthood
• Treat hearing loss and vision problems promptly rather than assuming they are an inevitable part of ageing
• Avoid heavy or prolonged alcohol use and smoking
• Treat depression and get adequate, good-quality sleep
• Protect against head injury where possible
• Seek assessment early for any noticeable, persistent change in memory or thinking rather than waiting

Families are central to dementia care in Nepal, and their involvement from the point of diagnosis makes a real difference. It helps to learn about the specific type of dementia diagnosed, since the expected course and best strategies differ between causes. Communication techniques matter: keeping instructions simple, allowing extra time, avoiding arguing about false beliefs or confused statements, and instead gently redirecting, tend to reduce distress for everyone. Safety planning — for wandering, medication management, cooking and driving — should be addressed proactively rather than after an incident. Legal and financial planning, including power of attorney arrangements, is best discussed while the person can still participate meaningfully in the decision. Caregiver burnout is common and is not a sign of failure; arranging respite, sharing responsibilities among family members, and seeking the caregiver's own medical and emotional support are a legitimate and necessary part of the overall care plan.

1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, 5th Edition, Text Revision (DSM-5-TR).
2. World Health Organization. Dementia fact sheet and ICD-11.
3. National Institute for Health and Care Excellence (NICE). Dementia: assessment, management and support.
4. Lancet Commission on Dementia Prevention, Intervention, and Care.