This cross-sectional study recruited TCK families in Switzerland between 2017 and 2021. Key findings: increased perceived stress leads to decreased resilience, which in turn leads to more mental health difficulties. Family functioning affects mental health although this variable does not mediate stress. Families in the sample communicated well about the move and provided safe spaces for TCKs, aligning with previous findings that family cohesion positively influences adjustment. The study uses a transdiagnostic framework (HiTOP and RDoC) to understand TCK mental health outcomes. Open access via Frontiers in Psychology.