The ten-eleven translocation 2 (Tet2) protein, a member of the Tet family, acts as an α-ketoglutarate- and Fe²⁺-dependent dioxygenase that catalyzes the iterative oxidation of 5-methylcytosine. Tet2 is widely recognized for its involvement in diverse physiological and pathological processes. Herein, we focused on Tet2 changes in stress-related disease models, behavioral changes in response to mutant forms of Tet2, and potential mechanisms underlying the involvement of Tet2 in psychiatric symptoms. This information can contribute to the comprehensive understanding of the role of Tet2 in stress-related disorders and its potential as a therapeutic target.