Fig. 4: Moderated mediation models.

A Antenatal stress led to a significant decrease in the time dams spent in the open arms of the maze on PND 1 (a₁ = −0.15, p < 0.0001); chronic treatment with either escitalopram (b₄ = −0.66, p = 0.0007) or shan-zha (b₅ = −0.53, p = 0.009) to lactating dams that were exposed to antenatal stress significantly moderated the association between dams’ and pups’ anxiety. Higher values on the anxiety indices indicate diminished anxiety-like-behavior. N = 221. B Chronic treatment with escitalopram led to a significant decrease in dams’ free SERT (a₁ = −1.06, p < 0.0001); exposure to antenatal stress served as a precursor for the association between dams’ and pups’ free SERT (b₄ = 0.39, p = 0.002), suggesting that antenatal stress exacerbated the transfer of escitalopram from dams to pups via lactation. N = 90. C A graphical depiction of the hypothesized mechanism by which antenatal stress might exacerbate pups’ exposure to escitalopram; putatively, via durable alterations of the permeability of the mammary glandular epithelium that is instigated in the critical stage of mid-to-late gestation. Created with BioRender.com. Esc escitalopram, TJ tight junction. *p < 0.05, **p < 0.01, ***p < 0.001.