MDD (major depressive disorder) is a highly prevalent mental disorder with a complex etiology involving behavioral and neurochemical factors as well as environmental stress. The interindividual variability in response to stress stimuli may be explained by processes such as long-term potentiation (LTP) and long-term depression (LTD). LTP can be described as the strengthening of synaptic transmission, which translates into more efficient cognitive performance and is regulated by brain-derived neurotrophic factor (BDNF), a protein responsible for promoting neural growth. It is found in high concentrations in the hippocampus, a part of the limbic system which is far less active in people with MDD. Omega-3 fatty acids like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) not only contribute to structural and antioxidative functions but are essential for the maintenance of LTP and stable BDNF levels. This review explores the mechanisms and potential roles of omega-3 fatty acids in the prevention of MDD.

MDD（重度抑郁症）是一种非常普遍的精神障碍，其病因复杂，涉及行为和神经化学因素以及环境压力。对应激刺激反应的个体差异可以通过长时程增强（LTP）和长时程抑制（LTD）等过程来解释。LTP 可以被描述为突触传递的加强，从而转化为更有效的认知表现，并受到脑源性神经营养因子 (BDNF) 的调节，BDNF 是一种负责促进神经生长的蛋白质。它在海马体中含量很高，海马体是边缘系统的一部分，在重度抑郁症患者中，其活性要低得多。Omega-3 脂肪酸如二十碳五烯酸 (EPA) 和二十二碳六烯酸 (DHA) 不仅有助于结构和抗氧化功能，而且对于维持 LTP 和稳定的 BDNF 水平至关重要。本综述探讨了 omega-3 脂肪酸在预防 MDD 中的机制和潜在作用。