Age-specific determinants of psychiatric outcomes after the first COVID-19 wave: baseline findings from a Canadian online cohort study

BACKGROUND: Canadians endured unprecedented mental health (MH) and support access challenges during the first COVID-19 wave. Identifying groups of individuals who remain at risk beyond the acute pandemic phase is key to guiding systemic intervention efforts and policy. We hypothesized that determinants of three complementary, clinically actionable psychiatric outcomes would differ across Canadian age groups. METHODS: The Personal Impacts of COVID-19 Survey (PICS) was iteratively developed with stakeholder feedback, incorporating validated, age-appropriate measures. Baseline, cross-sectional online data collected between November 2020-July 2021 was used in analyses. Age group-specific determinants were sought for three key baseline MH outcomes: (1) current probable depression, generalized anxiety disorder, obsessive–compulsive disorder and/or suicide attempt during COVID-19, (2) increased severity of any lifetime psychiatric diagnosis, and (3) inadequate MH support access during COVID-19. Multivariable logistic regression models were constructed for children, youth (self- and parent-report), young adults (19–29 years) and adults over 29 years, using survey type as a covariate. Statistical significance was defined by 95% confidence interval excluding an odds ratio of one. RESULTS: Data from 3140 baseline surveys were analyzed. Late adolescence and early adulthood were identified as life phases with the worst MH outcomes. Poverty, limited education, home maker/caregiver roles, female and non-binary gender, LGBTQ2S + status and special educational, psychiatric and medical conditions were differentially identified as determinants across age groups. INTERPRETATION: Negative psychiatric impacts of COVID-19 on Canadians that include poor access to MH support clearly persisted beyond the first wave, widening pre-existing inequity gaps. This should guide policy makers and clinicians in current and future prioritization efforts. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13034-023-00560-8.