Postpartum mental illness during the COVID-19 pandemic: a population-based, repeated cross-sectional study

BACKGROUND: It is unclear whether the clinical burden of postpartum mental illness has increased during the COVID-19 pandemic. We sought to compare physician visit rates for postpartum mental illness in Ontario, Canada, during the pandemic with rates expected based on prepandemic patterns. METHODS: In this population-based, repeated cross-sectional study using linked health administrative databases in Ontario, Canada, we used negative binomial regression to model expected visit rates per 1000 postpartum people for March–November 2020 based on prepandemic data (January 2016–February 2020). We compared observed visit rates to expected visit rates for each month of the pandemic period, generating absolute rate differences, incidence rate ratios (IRRs) and their 95% confidence intervals (CIs). The primary outcome was a visit to a primary care physician or a psychiatrist for any mental disorder. We stratified analyses by maternal sociodemographic characteristics. RESULTS: In March 2020, the visit rate was 43.5/1000, with a rate difference of 3.11/1000 (95% CI 1.25–4.89) and an IRR of 1.08 (95% CI 1.03–1.13) compared with the expected rate. In April, the rate difference (10.9/1000, 95% CI 9.14–12.6) and IRR (1.30, 95% CI 1.24–1.36) were higher; this level was generally sustained through November 2020. From April–November, we observed elevated visit rates across provider types and for diagnoses of anxiety, depressive and alcohol or substance use disorders. Observed increases from expected visit rates were greater for people 0–90 days postpartum compared with 91–365 days postpartum; increases were small among people living in low-income neighbourhoods. Public health units in the northern areas of the province did not see sustained elevations in visit rates after July; southern health units had elevated rates through to November. INTERPRETATION: Increased visits for mental health conditions among postpartum people during the first 9 months of the COVID-19 pandemic suggest an increased need for effective and accessible mental health care for this population as the pandemic progresses.