title: Dementia can affect an individual's personhood.
abstract: This article defines three levels of personhood: ■ Biological personhood: Central to biological system is sentience or the ability to experience pleasure or pain. There is little disagreement that all individuals living with dementia retain personhood at a basic biological level. ■ Individual personhood: This relates to an individual's characteristics including such things as the past, roles, personality, values, self-worth and spirituality. ■ Sociological personhood: This is defined by the perceptions of society and other people's approach to the person with dementia. As social contacts become aware of cognitive decline, their behaviour towards the individual begins to change. Residents become more isolated and sociological personhood is threatened. Individuals living in nursing homes can become increasingly socially isolated.