Did childhood adversity increase the vulnerability of university students to the negative mental health impact of the COVID-19 pandemic?

OBJECTIVE: To examine a potential synergistic effect of history of childhood adversity and COVID-19 pandemic exposure on the association with mental health concerns in undergraduate students. Participants: We used U-Flourish Survey data from 2019 (pre-pandemic) and 2020 (during-pandemic) first-year cohorts (n = 3,149) identified at entry to a major Canadian University. METHODS: Interactions between childhood adversity (physical and sexual abuse, and peer bullying) and COVID-19 pandemic exposure regarding mental health concern (depressive and anxiety symptoms, suicidality, and non-suicidal self-harm) were examined on an additive scale. RESULTS: We found a positive additive interaction between physical abuse and pandemic exposure in relation to suicidality (combined effect was greater than additive effect (risk difference 0.54 vs. 0.36)). Conversely, less than additive interactions between peer bullying and pandemic regarding depression and anxiety were observed. CONCLUSIONS: Childhood adversities have diverse reactions to adult stressor depending on the nature of the childhood adversity and the mental health outcomes.