Stress-related disorders, encompassing conditions such as anxiety, depression, and post-traumatic stress disorder (PTSD), pose significant challenges to global mental health. While the etiology of these disorders involves a complex interplay of genetic, environmental, and psychosocial factors, emerging evidence suggests a pivotal role of epigenetic modifications in their pathogenesis. Epigenetic mechanisms, including DNA methylation, histone modifications, and non-coding RNA-mediated regulation, dynamically regulate gene expression in response to stressors, thereby influencing brain function and behaviour. Alterations in these epigenetic processes contribute to aberrant stress responses, increased susceptibility to stress-related disorders, and individual differences in stress vulnerability and resilience. Moreover, epigenetic modifications can be transmitted across generations, highlighting the enduring impact of stress on mental health outcomes. Understanding the mechanisms underlying epigenetic regulation in stress-related disorders provides insights into disease pathogenesis and potential biomarkers for diagnosis and prognosis. Additionally, targeting epigenetic pathways represents a promising therapeutic approach for these disorders. Epigenetic drugs, such as DNA methyltransferase inhibitors and histone deacetylase inhibitors, hold potential for mitigating the adverse effects of stress on mental health. However, challenges such as off-target effects and lack of specificity necessitate further refinement of epigenetic-based therapies.