Suicide and Alzheimer's pathology in the elderly: A case-control study

Background: The single most important risk factor for Alzheimer's pathology is age. Elderly individuals are also at increased risk for suicide, but co mprehensive studies of the association between Alzheimer's pathology and su icide are lacking. We designed the current study to determine if Alzheimer' s disease changes are overrepresented in elderly people committing suicide. Methods: The design is a case-control study. Cases (n = 28) were subjects o lder than 60 years of age who completed suicide. For each case, two age- an d gender-matched individuals who died naturally,were selected as control su bjects (n = 56), Neuropathologic examination of hippocampal sections was pe rformed blindly and included a modified Braak scoring system and semiquanti tative assessment of neurofibrillary tangles. amyloid deposition, Lewy bodi es, and Lewy-associated neurites. Data,were analyzed by conditional logisti c regression. Results: The brains of individuals who committed suicide had higher modifie d Braak scores than those of matching control subjects (p = .0028), The num ber of neurofibrillary tangles in CAI was not an independent predictor of s uicide status in the statistical analysis (p = .16), although the distribut ion was more highly skewed among the cases (75th percentile of 10.5 for cas es, vs. 2 for control subjects), Conclusions: Severe Alzheimer's disease pathology is overrepresented in eld erly patients who complete suicide. (C) 2001 Society of Biological Psychiat ry.