There is growing awareness that the subjective experience of people with dementia is important for understanding behavior and improving quality of life. This paper reviews and reflects on the currently available theories on subjective experience in dementia and it explores the possibility of a knowledge gap on the influence of neurological deficits on experience in late stage dementia.

A literature review on current commonly used theories on experience in dementia was supplemented with a systematic review in PubMed and Psychinfo. For the systematic review, the terms used were Perception and Dementia and Behavior; and Awareness and Dementia and Long term care.

Current models emphasize the psychosocial factors that influence subjective experience, but the consequences of neurological deficits are not elaborated upon. The systematic literature search on the neuropsychological functioning in dementia resulted in 631 papers, of which 94 were selected for review. The current knowledge is limited to the early stages of Alzheimer's disease. Next to memory impairments, perception of the direct environment, interpretation of the environment, and inhibition of own responses to the environment seem to be altered in people with dementia.

Without knowledge on how perception, interpretation and the ability for response control are altered, the behavior of people with dementia can easily be misinterpreted. Research into neuropsychological functioning of people in more severe stages and different forms of dementia is needed to be able to develop a model that is truly biopsychosocial. The proposed model can be used in such research as a starting point for developing tests and theories.

People with dementia may benefit from palliative care which specifically addresses the needs of patients and families affected by this life-limiting disease. On behalf of the European Association for Palliative Care (EAPC), we recently performed a Delphi study to define domains for palliative care in dementia and to provide recommendations for optimal care. An international panel of experts in palliative care, dementia care or both, achieved consensus on almost all domains and recommendations, but the domain concerning the applicability of palliative care to dementia required revision.

To examine in detail, the opinions of the international panel of 64 experts around the applicability of palliative care, we explored feedback they provided in the Delphi process. To examine which experts found it less important or less applicable, ordinal regression analyses related characteristics of the panelists to ratings of overall importance of the applicability domain, and to agreement with the domain's four recommendations.

Some experts expressed concerns about bringing up end-of-life issues prematurely and about relabeling dementia care as palliative care. Multivariable analyses with the two outcomes of importance and agreement with applicability indicated that younger or less experienced experts and those whose expertise was predominantly in dementia care found palliative care in dementia less important and less applicable.

Benefits of palliative care in dementia are acknowledged by experts worldwide, but there is some controversy around its early introduction. Further studies should weigh concerns expressed around care receiving a “palliative” label versus the benefits of applying palliative care early.