Contrasting the amygdala activity and functional connectivity profile between antidepressant-free participants with major depressive disorder and healthy controls: A systematic review of comparative fMRI studies

•Neuroimaging results concerning the amygdala functioning in MDD are variable.•We reviewed amygdala functional imaging results in antidepressant-free MDD.•Among MDD participants, amygdala was hyperactive in response to negative stimuli.•MDD FC alteration between amygdala, PFC, ACC, insula, temporal, and parietal cortex.•Decreased connectivity between amygdala and OFC, striatum, and cerebellum in MDD.