Patients with hoarding disorder (HD) show difficulty discarding items due to the perceived need to save the items and to distress about discarding them, which causes domestic squalor (DS), especially in young people. In older people, dementia also causes DS. In this case series, we report five cases of older people with DS and compare DS due to HD with DS due to dementia.

Case 1 was an 82-year-old female who showed hoarding symptoms in her 60s. She was diagnosed with late-onset HD. Case 2 was a 73-year-old female who showed hoarding symptoms in her 10s. She was diagnosed with early-onset HD. Cases 1 and 2 showed difficulty discarding. Case 1 went to the dump site to collect items that had been discarded by her family. Case 2 strongly refused to throw away items that were considered unnecessary by her family. However, cases 1 and 2 could continue to live at home with nonpharmacological treatment, such as limiting shopping items and getting items from friends and discarding items with their family step by step. Case 3 was a 56-year-old male who showed hoarding symptoms in his 50s. Case 4 was a 72-year-old female who showed hoarding symptoms in her 60s. Cases 3 and 4 were diagnosed with behavioral variant frontotemporal dementia. Case 5 was a 67-year-old female who showed hoarding symptoms in her 60s. She was diagnosed with dementia with Lewy bodies. Case 3-5 did not feel distressed that their family discard their items in their absence. However, despite adjustments to their living environment, they could not continue to live at home and were admitted to a nursing home.

In this case series, although cases with DS due to HD showed difficulty discarding items, they could continue to live at home. However, in cases with DS due to dementia, although their house was easily cleaned, they cloud not continue to live at home due to impairment of their daily activities. Therefore, it is important not to miss HD in older people, and DS due to dementia may be a sign they have difficulty living at home.