Quality of life (QOL) has become an important outcome measure in the care of dementia patients. However, there have been few studies focusing on the difference in QOL between different dementias.

Two-hundred seventy-nine consecutive outpatients with Alzheimer's disease (AD), dementia with Lewy bodies (DLB) or frontotemporal dementia (FTD) were recruited. The QOL was evaluated objectively using the QOL Questionnaire for Dementia (QOL-D).The QOL-D comprises six domains: positive affect, negative affect and actions, communication, restlessness, attachment to others, and spontaneity. General cognition, daily activities, and behavioral and psychological symptoms of dementia were also evaluated.

The scores of positive affect of QOL-D of AD patients were significantly higher than those of patients with DLB or FTD (AD 3.1 ± 0.8, DLB 2.6 ± 0.9, FTD 2.6 ± 0.7). The scores of negative affect and action of QOL-D of FTD patients were significantly higher than those of patients with AD or DLB (FTD 2.0 ± 0.8, AD 1.4 ± 0.5, DLB 1.5 ± 0.6). The apathy scores of FTD and DLB patients were significantly higher than those of patients with AD. The disinhibition scores of FTD patients were significantly higher than those of patients with AD or DLB.

The apathy of FTD and DLB patients and depression of DLB patients might affect the lower positive affect of FTD and DLB patients compared to AD patients. The disinhibition of FTD patients might affect the abundance of negative affect & actions in FTD patients compared to AD and DLB patients.