Neuropathological analysis for aged suicide victims.

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K09263
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Legal medicine
• Research Institution: University of Toyama
• Principal Investigator: Nishida Naoki 富山大学, 学術研究部医学系, 教授 (10315088)
• Co-Investigator(Kenkyū-buntansha): 畑 由紀子 富山大学, 学術研究部医学系, 准教授 (30311674)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 自殺 / 神経病理学 / 免疫染色 / 気分障害 / 高齢者

Outline of Final Research Achievements

We investigated clinical and neuropathological appearance of 303 suicide victims (male;127 case, female; 176 cases) in our forensic autopsy unit, and compared with other non-suicide cases (844 cases, male;565, female; 279). Gallyas-Braak staining and Immunohistochemistry using anti-phosphorylated tau, a-synuclein, TDP-43 antibody were applied for all autopsy cases. As the results, the cases with history of psychiatric disorder in suicide cases was significantly higher than non-suicide cases. Although the prevalence of Alztheimer's disease related pathology was not significant in suicide cases, the prevalence of argyrophilic grain disease was significantly higher in suicide cases. Also Odd ratio of progressive supra nuclear palsy was high (1.615). Present study showed structural brain disease, especially 4 repeat tauopathy, may contribute to increase the risk of suicide attempt in elderly population.

Free Research Field

法医学、神経病理学、循環器病理学

Academic Significance and Societal Importance of the Research Achievements

世界的に自殺剖検例の神経病理学的検索はほとんど施行されておらず、神経変性疾患と自殺との関連についてはほとんど検証されていない。本研究は現時点で最も多数の自殺剖検例に対し詳細な神経病理学的検討を行ったものと考えられる。本研究結果は高齢者において，一部の器質的神経疾患、特に嗜銀顆粒症(argyrophilic grain disease)が自殺遂行に寄与している可能性を強く示唆した点で非常に意義が深く，今後、高齢者に対し神経学的所見を正確に評価することが、正確な自殺リスクの評価、自殺予防につながっていく可能性が示唆された。