Thus, the findings in this study may suggest a possible mechanism of stress-induced depression in which chronic stress upregulates the expression of TTR and TTR stimulates the expression of inflammation-related genes such as Lcn2, Icam1, and Vcam1, which in turn cause inflammatory responses, ultimately resulting in depression-like behavior coupled with cytotoxicity by TTR. Here, ICAM1 is linked to depressive symptom measurement.