Effects of the COVID-19 pandemic on suicidal ideation in a representative Australian population sample–Longitudinal cohort study

Objective: The direct and indirect mental health impacts of the COVID-19 pandemic are considerable. However, it is unclear how suicidal ideation was affected in communities during the acute lockdown phase of the pandemic, and over the longer-term. This study provides longitudinal data on the prevalence of, and risk factors for, suicidal ideation in the Australian national population, during the pandemic. Method: The Australian National COVID-19 Mental Health and Risk Communication Survey assessed a nationally representative sample of Australian adults (N = 1296) fortnightly for 12 weeks from late-March to June 2020 (7 waves), and again in March 2021 (wave 8). Cox proportional hazards models examined demographic and pandemic-related risk factors for suicidal ideation over time. Results: Prevalence of suicidal ideation was high but steady at ∼18% across the acute lockdown phase of the pandemic, and 16.2% in March 2021. People who had direct experience with COVID-19 (tested, diagnosed, or contact with someone who was diagnosed) had increased risk for suicidal ideation. Higher pandemic-related work and social impairment, recent adversity, loneliness, and being younger were also associated with increased risk of suicidal ideation over time. Conclusion: Both the direct and indirect impacts of COVID-19 were associated with increased risk for suicidal ideation over time, although prevalence did not vary over time. The high prevalence of suicidal ideation in our sample flags a critical need for accessible mental health support, and findings provide insights into the factors placing people at risk during the pandemic.