编辑“︁自殺”︁（章节）

==病理生理學==
对于任何自杀或抑郁症来说，尚未找到统一的基本[[病理生理學]]来进行解释。<ref name=EB2011/>但普遍认为这是由于行为因素、社会环境因素和精神因素相互影响所导致的。<ref name=Yip2012/>

低水平的[[脑源性神经营养因子]]（BDNF）与自杀有直接相关性，<ref>{{cite journal|last=Pjevac|first=M|author2=Pregelj, P|title=Neurobiology of suicidal behaviour.|journal=Psychiatria Danubina|date=2012-10|volume=24 Suppl 3|pages=S336-41|pmid=23114813}}</ref>并与重度抑郁症、创伤后应激障碍、精神分裂症和[[强迫症]]有着间接相关性。<ref>{{cite journal|last=Sher|first=L|title=The role of brain-derived neurotrophic factor in the pathophysiology of adolescent suicidal behavior.|journal=International journal of adolescent medicine and health|year=2011|volume=23|issue=3|pages=181–5|pmid=22191181}}</ref>[[验尸|尸体剖检]]研究发现[[海马体]]和[[前额叶皮质]]中的BDNF有所下降，不论该死者是否患有精神疾病。<ref>{{cite journal|last=Sher|first=L|title=Brain-derived neurotrophic factor and suicidal behavior.|journal=QJM : monthly journal of the Association of Physicians|date=2011 May|volume=104|issue=5|pages=455–8|pmid=21051476|doi=10.1093/qjmed/hcq207}}</ref>[[血清素]]是一种大脑中的[[神经递质]]，它被认为在自杀人群中水平较低。一方面，人们发现在死亡后，人体中的[[5-HT2A受体]]水平有所提高。<ref name=Dwi2012>{{cite book|last=Dwivedi|first=Yogesh|title=The neurobiological basis of suicide|year=2012|publisher=Taylor & Francis/CRC Press|location=Boca Raton, FL|isbn=978-1-4398-3881-5|page=166|url=http://books.google.ca/books?id=5hcOf_SM-U0C&pg=PA166|access-date=2014-02-02|archive-date=2013-10-05|archive-url=https://web.archive.org/web/20131005123507/http://books.google.ca/books?id=5hcOf_SM-U0C&pg=PA166|dead-url=no}}</ref>其他一些证据包括[[脑脊液]]中的血清素和[[5-羟吲哚乙酸]]的水平出现下降。<ref>{{cite book|last=Stein|first=edited by George|title=Seminars in general adult psychiatry|year=2007|publisher=Gaskell|location=London|isbn=978-1-904671-44-2|page=145|url=http://books.google.ca/books?id=6PGzHFuS1xkC&pg=PA145|edition=2nd|author2=Wilkinson, Greg|access-date=2014-02-02|archive-date=2020-06-14|archive-url=https://web.archive.org/web/20200614225927/https://books.google.ca/books?id=6PGzHFuS1xkC&pg=PA145&hl=en|dead-url=no}}</ref>但与此相关的直接证据却是很难搜集的。<ref name=Dwi2012/>[[表观遗传学]]是一种研究不改变[[DNA基因序列]]的环境因素所致的基因表达水平变化的科学，而它也被认为在决定自杀风险时起到了一定作用。<ref>{{cite journal|last=Autry|first=AE|author2=Monteggia, LM|title=Epigenetics in suicide and depression.|journal=Biological Psychiatry|date=2009-11-01|volume=66|issue=9|pages=812–3|pmid=19833253|doi=10.1016/j.biopsych.2009.08.033|pmc=2770810}}</ref>