BackgroundAs an emergent developmental construct, derailment – an individual difference hallmarked by a temporal discordance of the self – has been positively associated with depressive features, though less is known about the role of stress in this relationship. The aim of the present study was to explore the interaction between derailment and subjective stress on depressed mood. Methods265 adults recruited through Prolific – a crowd sourcing platform were first tasked with completing baseline measures, then were randomly assigned to a low stress or high stress condition. We utilized an adapted version of the Online Trier Stress Test to manipulate stress levels. Next, depressed mood and post-test perceived stress were measured. We analyzed data through STATA using a two-tailed independent samples t-test and multiple linear regression. ResultsFindings suggested the experimental manipulation increased subjective stress within the high stress condition compared to the low stress condition (Mdiff = 36.14, SE = 4.4, t = 8.21, p < .001). Further, we found the interaction between derailment and stress conditions was associated with increased depressed mood (β = −0.11, SE = 0.05, p = .038, R2 = 0.5). Notably, we found significant between-condition differences in depressed mood for those who endorsed either low (d = 0.22, SE = 0.07, p = .003) or moderate levels of derailment (d = 0.11, SE = 0.05, p = .033), but not for those who endorsed high levels of derailment (d = 0.01, SE = 0.07, p = .92). LimitationsThis study utilized self-report measures, which may be susceptible to biased responses. ConclusionsDerailment may play a role in the persistence of depressed mood regardless of varying contexts of stress.