The Burden of the Past: A Systematic Review of Childhood Trauma and Mental Health in Transgender and Gender Nonconforming Individuals.

Adverse childhood experiences (ACEs) are critical determinants of long-term psychological and physiological health outcomes. Transgender and gender nonconforming (TGNC) individuals are at increased risk for ACEs, including family rejection, peer victimization, and systemic discrimination. Despite the growing body of research on this topic, an updated synthesis of recent literature is needed to understand the evolving landscape of ACE-related risks and protective factors in TGNC populations. This systematic review, conducted according to PRISMA guidelines, examined studies published between 2020 and 2024 that were related to the association between ACEs and mental health outcomes in TGNC individuals. A comprehensive database search yielded 6124 articles, 42 of which met the inclusion criteria. Data extraction focused on the type of ACEs reported, associated mental health outcomes, resilience factors, and clinical implications. The results showed that TGNC individuals are significantly more likely to experience childhood maltreatment, including emotional, physical, and sexual abuse, as well as transphobia-specific ACEs such as forced gender conformity and identity denial. These experiences are associated with an increased risk of depression, PTSD, suicidality, and substance use disorders. Family rejection was found to be a critical risk factor, while social support, gender-specific care, and self-efficacy showed protective effects. The reviewed studies emphasize the urgent need for trauma-informed and gender-affirming mental health interventions to mitigate the effects of ACEs on TGNC individuals. Limitations and future research directions are discussed.