From pre-pandemic to pandemic: Unravelling mental health trajectories in clinical and general population cohorts

Background: The COVID-19 pandemic is often portrayed as a universal mental health crisis, especially in studies lacking pre-pandemic data. Research including pre-pandemic measures nonetheless yields mixed results, making the pandemic’s impact on mental health unclear, particularly when considering differences between general and clinical populations.Aims: This study examined depression and anxiety trajectories from pre-pandemic to peri-pandemic phases in general and clinical populations. It also explored how symptom trajectories varied by sociodemographic and pandemic-related factors.Method: Data from six cohorts in Germany, France, and the Netherlands were pooled within the Co-RESPOND project, comprising 2,796 participants. Cohorts were included based on available pre-pandemic data and at least two peri-pandemic assessments. Anxiety and depression symptoms were assessed using standardized measures and converted to z-scores for cross-cohort comparability. Symptom trajectories were identified using Latent Growth Mixture Modelling, and logistic regressions examined predictors of trajectory membership.Results: Participants had a median age of 42.3 years, with 65.6% being women. In the general population, approximately 80% showed decreasing symptoms, even among those with higher initial severity, while 20% maintained consistently low levels. In the clinical population, approximately half showed improvements from moderate symptom levels, with the remainder exhibiting consistently high or low symptoms. In the general population, divorce/separation and having children predicted more favourable anxiety and depression trajectories, while older age and childcare burden predicted less favourable trajectories. In the clinical population, being in a relationship, older age, and being a man were linked to more favourable anxiety trajectories.Conclusions: This study provides substantial evidence to refute the notion of the COVID-19 pandemic as a universal mental health crisis, showing that most adults across both general and clinical populations experienced stable or improving symptoms. Our findings underscore the need for mental health surveillance and responses that are proportionate and targeted, focusing on groups most at risk.