SKA2 and major depressive disorder: The observed interaction is similar to that reported for other HPA axis-relevant genes including CRHR1 and FKBP5. In both cases, high CTQ scores moderate the relationship between genetic variation and psychiatric symptoms or HPA–axis function.26, 27 Indeed, FKBP5 has also been associated with depression, anxiety and PTSD.28, 29, 30, 31 Such interactions with childhood maltreatment, including those observed for SKA2, may result from a differential priming of the HPA axis by early-life trauma.