Data from four consecutive cohorts of students in Australia (2019-2022) show the impact of the COVID-19 pandemic on domestic and international university students' mental health.

Introduction: COVID-19 and related travel and social restrictions caused significant stress for university students in Australia and globally. Learning quickly moved online and many students (particularly international students) were separated from social and economic support. This study examined the impact of the pandemic from pre-pandemic (2019) to the COVID-19 Omicron wave (2022) on domestic and international students' mental health.

Methods: Participants were 1540 students (72% females, 28% international) in four first-year cohorts (2019, 2020, 2021, 2022). We screened for mental health concerns (% positive) and symptom scores for depression, anxiety and somatic distress using the PsyCheck, and general wellbeing using the Warwick-Edinburgh Mental Well-being scale.

Results: From pre-COVID (2019) to the first wave of COVID-19 (2020), the proportion of students screening positive for mental health problems rose in both domestic students (66-76%) and international students (46-67%). Depression symptoms and wellbeing were worse in 2020 than in 2019, 2021 and 2022. Anxiety symptoms increased from 2019 to 2020 and continued to rise in 2021 and 2022. Somatic symptoms did not show an effect of cohort. Contrary to expectations, domestic students reported higher distress and lower wellbeing than international students across cohorts.

Conclusion: The pandemic was associated with a marked increase in psychological distress in first-year university students, not all of which settled with the easing of restrictions. Post-pandemic recovery in the Australian university sector must include university-wide access to mental health information and support for incoming students.