The reduction in the oxygenation dynamics in the prefrontal cortex (PFC) during cognitive tasks is a well-known occurrence in major depressive disorders (MDD). Studies focusing on oxygenation changes in the PFC in individuals with suicidal ideation are limited. Therefore, this study investigated and confirmed the presence of prefrontal dysfunction depending on the intensity of suicidal ideation among 77 young adults (45 patients with MDD and 32 healthy controls) using near-infrared spectroscopy (NIRS). All participants underwent assessment with the Beck Depression Inventory-II, Beck Anxiety Inventory, and Beck Scale for Suicidal ideation. NIRS revealed relative hypofunction in the left dorsolateral PFC, left ventrolateral PFC (LVLPFC), and both orbitofrontal cortices in young adults with MDD compared to that in the healthy controls during verbal fluency tasks. Furthermore, the oxyhaemoglobin changes in the LVLPFC mediated the indirect effect of depression severity on suicidal ideation intensity. Our results confirmed that functional NIRS is a useful auxiliary tool for objectively assessing the risk of suicidal ideation.

认知任务期间前额叶皮层（PFC）的氧合动力学降低是众所周知的主要抑郁症（MDD）事件。侧重于具有自杀意念的个人中PFC的氧合变化的研究非常有限。因此，本研究使用近红外光谱法（NIRS）调查并确认了前额功能障碍的存在，这取决于自杀意念的强度，该意念存在于77名年轻成年人（45名MDD患者和32名健康对照）中。所有参与者均接受了《贝克抑郁量表-II》，《贝克焦虑量表》和《贝克自杀意念量表》的评估。NIRS显示左背外侧PFC，左腹外侧PFC（LVLPFC）相对功能减退，在口语流利任务中，与健康对照相比，患有MDD的年轻成年人的眶额皮质都比较好。此外，LVLPFC中的氧合血红蛋白变化介导了抑郁严重程度对自杀意念强度的间接影响。我们的结果证实，功能性NIRS是客观评估自杀意念风险的有用辅助工具。