In social mammalian species, social stress can arise from different social interactions. Repeated exposure to social stressors can lead to neuropathology and psychiatric disorders. In this issue, Sakamoto et al. report on alterations in extracellular vesicles (EVs) in a mouse model of chronic social defeat stress (CSDS). The data suggest that mice susceptible to CSDS have alterations in the miRNA content of circulating EVs, which influences the expression of pro-inflammatory cytokines in microglia cells.