Investigation of Alzheimer's disease-related pathology in community dwelling older subjects who committed suicide

Older people have a higher risk of completed suicide than any other age group worldwide. The contribution of neurodegenerative disease to this risk remains controversial.

To investigate prevalence of Alzheimer's disease-related (AD) pathology in older suicide victims.

Ratings of AD pathology using Braak and CERAD protocols were compared in 143 community-dwelling suicide victims aged 65 years or more and 59 motor vehicle accident victims autopsied at the request of an Australian Coroner's Court.

There were no significant differences in plaque score or neurofibrillary tangle staging between suicide and control groups. None of the subjects with a history of dementia had neuropathologically confirmed AD.

Our study is the second and largest investigation of the prevalence of AD neuropathology in the elderly suicide population. Unlike the previous study, we did not find an increased prevalence of AD neuropathology despite a history of dementia in 6.3%, implicating other pathologies such as Lewy Body or Vascular dementia in the aetiology of dementia in elderly suicide victims.