Dementia is a chronic organic brain syndrome, characterised by progressive impairment of multiple cortical functions, including memory, learning, orientation, language, comprehension, and judgement. Diagnosis requires decline in cognitive function and independent living skills (Box 1
. However, for carers and people with dementia, the behavioural and psychological symptoms of dementia (BPSD) affect most quality of life, are an important cause of carer strain 
, and a common reason for institutionalisation 
. Alzheimer's disease, vascular dementia, dementia with Lewy bodies, and frontotemporal dementia are the most common dementia subtypes, but mixed pathologies may be the norm 
. Some rare causes (subdural haematoma, normal pressure hydrocephalus, hypercalcaemia, and deficiencies of thyroid hormone, vitamin B12, and folic acid) can be treated. Otherwise, the progressive course of dementia cannot be altered, but symptomatic treatments and support can be helpful.
Box 1. International Classification of Diseases 10 Criteria for Dementia and Commonly Occurring Features
Diagnostic criteria (ICD-10 Diagnostic Guidelines)
“The primary requirement for diagnosis is evidence of a decline in both memory and thinking which is sufficient to impair personal activities of daily living. The impairment of memory typically affects the registration, storage, and retrieval of new information, but previously learned and familiar material may also be lost, particularly in the later stages. There is also impairment of thinking and of reasoning capacity, and a reduction in the flow of ideas. The processing of incoming information is impaired, in that the individual finds it increasingly difficult to attend to more than one stimulus at a time, such as taking part in a conversation with several persons, and to shift the focus of attention from one topic to another. If dementia is the sole diagnosis, evidence of clear consciousness is required. The above symptoms and impairments should have been evident for at least 6 months for a confident clinical diagnosis of dementia to be made” 
The diagnostic criteria do not convey a sense of the typical progression of the disorder:
A person with mild dementia has noticed deterioration in their memory for recent events. For example, they may forget that their daughter had visited the previous day. They also find it difficult to concentrate, think flexibly, plan, and take decisions. They are likely to feel bewildered, anxious and sad. They may become angry and defensive when others point out errors.
A person with moderate dementia has severe memory problems. Only early memories are retained. Recent events are not remembered, or rapidly forgotten. They may not know the day, date or time of day. They often do not know where they are. They cannot communicate clearly, having problems finding the right word and using the wrong words. They may hear voices or see things that are not there, and can develop false beliefs, for example that children are entering their house and stealing things. They are likely to be anxious, sad, bewildered, and can become agitated or aggressive.
A person with severe dementia has complete memory loss. They may no longer recognise their close family. They have severe speech difficulties or are unable to communicate. They may be apathetic and totally inactive, but at times can be agitated and verbally and physically aggressive. They cannot coordinate their physical movements; may have lost the ability to walk and feed themselves and have difficulty swallowing. They are likely to be incontinent.
Dementia mainly affects older people. Few cases start before the age of 65 y, after which prevalence doubles with every 5-y increase in age 
. Globally, 24.3 million people are affected by dementia and 4.6 million new cases occur annually 
. The prevalence of dementia is expected to double every 20 y, reaching 81.1 million by 2040, an increase of 100% in developed countries and of more than 300% in India, China, and their neighbours. Prevalence is lower in low- and middle-income countries (LMICs) than in high income countries (HICs) 
, perhaps because of underdetection of mild cases 
. Nevertheless, most people with dementia live in LMICs—60% in 2001 rising to 71% by 2040 
Dementia contributes 11.2% of years lived with disability among people aged 60 y and over, a higher proportion than stroke (9.5%), musculoskeletal disorders (8.9%), cardiovascular disease (5.0%), and cancer (2.4%) 
. Its global cost is estimated to be US$317 billion, 77% of this total arising in HICs where formal sector care costs increase with disease progression, and institutionalization is the main cost driver 
. Family care is more important in resource-poor countries, accounting for 56% of costs in low-income countries, 42% in middle-income countries, and 31% in HICs 
. In a pilot study in 26 LMIC centers, carers were economically disadvantaged 
. A fifth of carers had cut back on paid work, and paid carers were common, which added to the economic strain 
. Compensatory benefits were practically nonexistent 
In three qualitative studies in India, features of dementia were widely recognized and named 
. However, dementia was perceived as normal ageing rather than as a medical condition. The consequences were limited help seeking 
despite disability and carer strain 
, no structured training on the recognition and management of dementia, and no constituency to advocate for more responsive care services 
. People with dementia were excluded from residential care 
. Carers misinterpreted BPSD as deliberate misbehavior 
. BPSD can also lead to stigma and blame attaching to the carers 
. In India, likely causes of dementia were cited as “neglect by family members, abuse, tension and lack of love” 
In this article, we focus on the effective management of dementia in LMICs, reviewing the evidence on efficacy of interventions and their delivery derived from LMICs where possible. Given the paucity of relevant evidence from LMICs, we also cite systematic reviews and meta-analyses based on trials from HICs. On the basis of our review we propose a package of care—a combination of treatments aimed at improving the recognition and management of conditions to achieve optimal outcomes—for dementia.