Mann J J, Oquendo M, Underwood M D, Arango V
Department of Neuroscience, New York State Psychiatric Institute, Columbia University College of Physicians & Surgeons, New York 10032, USA.
J Clin Psychiatry. 1999;60 Suppl 2:7-11; discussion 18-20, 113-6.
Suicidal behavior has neurobiological determinants independent of the psychiatric illnesses with which it is associated. We have found that some patients with major depression are vulnerable to acting on suicidal impulses. This vulnerability results from the interaction between triggers or precipitants and the threshold for suicidal behavior. An important factor in setting an individual's threshold for acting on suicidal impulses is brain serotonergic function. Serotonin function has been shown to be lower in suicide attempters by studies measuring serotonin metabolites in cerebrospinal fluid and studies of prolactin response to fenfluramine. Postmortem studies of suicide victims also reveal decreased serotonin activity in the ventrolateral prefrontal cortex. New neuroimaging paradigms, such as positron emission tomography (PET), offer an opportunity to visualize serotonin function in vivo in a more direct way than has previously been available. This technology may provide the possibility of timely therapeutic intervention in patients at high risk for suicide.
自杀行为具有独立于其所伴发精神疾病的神经生物学决定因素。我们发现，一些重度抑郁症患者容易产生自杀冲动行为。这种易感性源于触发因素或促发因素与自杀行为阈值之间的相互作用。设定个体对自杀冲动做出反应阈值的一个重要因素是大脑血清素功能。通过测量脑脊液中血清素代谢产物的研究以及对氟苯丙胺催乳素反应的研究表明，自杀未遂者的血清素功能较低。对自杀受害者的尸检研究也显示腹外侧前额叶皮质的血清素活性降低。新的神经影像学范式，如正电子发射断层扫描（PET），提供了一种比以往更直接的方式在体内可视化血清素功能的机会。这项技术可能为有高自杀风险的患者提供及时治疗干预的可能性。
