Abstract: Cognitive impairment is a typical feature of mood disorders. Mood disorders include major depressive disorder (MDD) and bipolar disorder (BD). Cognitive impairment affects a patient's daily and social abilities. Therefore, in order to improve the quality of life, patients need to optimize their cognitive functions. In general, cognitive impairment develops as BD progresses, and cognitive impairment is more severe than depression. In this review， we discuss the differences of cognitive function in patients with MDD and BD. Four aspects were elaborated: ① comparison of cognitive function of MDD and BD patients； ② imaging identification of cognitive impairment；  ③ factors affecting cognitive impairment；  ④ therapeutic strategies for improving cognitive function.

Key words: bipolar disorder, cognitive impairment, treatment strategy