抑郁症是一种常见精神疾病,主要表现为持续两周以上的情绪低落。世界卫生组织预测在2030年抑郁症的疾病负担将高居所有疾病、伤残总负担的榜首。抑郁症面临三大难题:1)发病机理不完全清楚,因而缺乏有效的预测预防途径和生物学诊断;2)现有单胺类抗抑郁症药物起效慢,也可能导致患者自杀风险增加;3)缺乏副作用小的非单胺类快速起效抗抑郁症药物。针对这三大难题,长期以来,应用抑郁症啮齿类模型的众多研究并未取得实质性进展,至少部分因素归咎于啮齿类与人类大脑功能的极大种属差异。树鼩是灵长类近亲,具有更接近于人类的大脑功能。本文针对抑郁症发病机理假说、临床表象和抗抑郁症药物疗效等内容,综述了社会竞争失败病因学的抑郁症树鼩模型可能会具有更好的疾病同源性、表象一致性和药物预见性。这一被长期忽视的抑郁症树鼩模型尽管还需要进一步完善,但对其进一步深入研究可能为解决抑郁症的三大难题提供了一条新途径。
Depression is a common neuropsychiatric disorder,marked by depressed mood for at least two weeks.The World Health Organization predicts that depression will be the number one leading cause of disease and injury burden by 2030.Clinical treatment faces at least three serious obstacles.First,the disease mechanism is not fully understood and thus there are no effective ways to predict and prevent depression and no biological method of diagnosis.Second,available antidepressants are based on monoamine mechanisms that commonly have a long delay of action and possibly cause a higher risk of suicide.Third,no other antidepressant mechanisms are available,with fast action and few side effects.Unfortunately,several decades of research based on rodent models of depression have not been successful in resolving these problems,at least partially due to the huge differences in brain function between rodents and people.Tree shrews are the closest sister to primates,and brain functions in these species are closer to those of humans.In this review,we discuss a tree shrew model of depression with social defeat etiology and aspects of construct,face and predicted validity of an animal model.Although a tree shrew model of depression has long been ignored and not fully established,its similarities to those aspects of depression in humans may open a new avenue to address this human condition.