Awareness is the recognition of changes caused by deficits related to the dementia process. Awareness is related to a given object, like memory functioning or functional status. Objects of awareness can be grouped into a range of domains, including cognition, functional ability, emotional and social functioning, and behavioral difficulties. Preserved awareness in people with young onset dementia (YOD) has been reported; however, there is a lack of research investigating whether there are differences in the domains of awareness impairment according to the age at onset of dementia. This study compared the differences in awareness and its domains and examined associations with cognition, functionality, neuropsychiatric symptoms, social and emotional functioning, and quality of life (QoL) among people with YOD and late onset dementia (LOD).

A group of 136 people with dementia and their caregivers (YOD= 50 and LOD= 86) were consecutively selected. We assessed awareness of disease, dementia severity, cognition, functionality, neuropsychiatric symptoms, social and emotional functioning, and QoL.

People with YOD presented more neuropsychiatric symptoms and worse cognition and functional ability than those with LOD. Compared to people with LOD, there were higher levels of awareness total score, awareness of cognitive functioning and health condition, and awareness of functional activity impairments domains in people with YOD, even in the moderate stage of the disease. There were no significant differences between groups in the emotional state, and social functioning and relationships domains of awareness. Multivariate linear regressions showed that functionality had a broad relationship with awareness in people with YOD. In contrast, neuropsychiatric symptoms and QoL were more significant to the awareness of people with LOD.

Different clinical variables are associated with different domains in YOD and LOD groups, reinforcing the heterogeneity of awareness in dementia. Differences in awareness and its domains in YOD and LOD may be particularly relevant to enabling interventions focused on meeting their specific needs and those of their families.