Longitudinal analyses of depression and anxiety highlight greater prevalence during COVID-19 lockdowns in the Dutch general population and a continuing increase in suicidal ideation in young adults (preprint)

Objective: The pandemic of the coronavirus disease 2019 (COVID-19) has led to an increased burden on mental health. This study therefore investigated the development of major depressive disorder (MDD), generalized anxiety disorder (GAD), and suicidal ideation in the Netherlands during the first fifteen months of the pandemic and three nation-wide lockdowns. Methods: Participants of the Lifelines Cohort Study -a Dutch population-based sample- reported current symptoms of MDD and GAD, including suicidal ideation, according to DSM-IV criteria using a digital structured questionnaire. Between March 2020 and June 2021, 36,106 participants (aged 18-96) filled out a total of 629,811 questionnaires across 23 time points. Trajectories over time were estimated using generalized additive models and analyzed in relation to age, sex, and lifetime history of MDD/GAD to identify groups at risk. Results: We found non-linear trajectories for MDD and GAD with a higher number of symptoms and prevalence rates during periods of lockdown. The point prevalence of MDD and GAD peaked during the third hard lockdown at 2.88% (95% CI: 2.71%-3.06%) and 2.92% (95% CI: 2.76%-3.08%), respectively, in March 2021. Women, younger adults, and participants with a history of MDD/GAD reported significantly more symptoms. For suicidal ideation, we found a linear increase over time in younger participants which continued even after the lockdowns ended. For example, 4.63% (95% CI: 3.09%-6.96%) of 20-year-old participants reported suicidal ideation at our last measured time point in June 2021, which represents a 4.14x increase since the start of the pandemic. Conclusions: Our study showed greater prevalence of MDD and GAD during COVID-19 lockdowns suggesting that the pandemic and government enacted restrictions impacted mental health in the population. We furthermore found a continuing increase in suicidal ideation in young adults. This warrants for alertness in clinical practice and prioritization of mental health in public health policy.

Using symptom-based case predictions to identify host genetic factors that contribute to COVID-19 susceptibility (preprint)

Epidemiological and genetic studies on COVID-19 are hindered by inconsistent and limited testing policies to confirm SARS-CoV-2 infection. Recently, it was shown that it is possible to predict potential COVID-19 cases using cross-sectional self-reported disease-related symptoms. Using a previously reported COVID-19 prediction model, we show that it is possible to conduct a GWAS on predicted COVID-19 which benefits from a larger sample size in order to gain new insights into the genetic susceptibility of the disease. Furthermore, we find suggestive evidence that genetic variants for other viral infectious diseases do not overlap with COVID-19 susceptibility and that severity of COVID-19 may have a different genetic architecture compared to COVID-19 susceptibility. Our findings demonstrate the added value of using self-reported symptom assessments to quickly monitor novel endemic viral outbreaks in a scenario of limited testing. Should there be another outbreak of a novel infectious disease, then we recommend repeatedly collecting data of disease-related symptoms.

The Lifelines COVID-19 Cohort: a questionnaire-based study to investigate COVID-19 infection and its health and societal impacts in a Dutch population-based cohort (preprint)

The COVID-19 pandemic has affected billions of people around the world not only through the infection itself but also through its wider impact on public health and daily life. To assess the effects of the pandemic, a team of researchers across a wide range of disciplines developed and implemented the Lifelines COVID-19 questionnaire, leading to the development of the Lifelines COVID-19 cohort. This cohort is recruited from participants of the Lifelines prospective population cohort and the Lifelines NEXT birth cohort, and participants were asked to fill out detailed questionnaires about their physical and mental health and experiences on a weekly basis starting in late March of 2020 and on a bi-weekly basis staring in June 2020. The Lifelines region covers the three Northern provinces of the Netherlands-Drenthe, Groningen and Friesland-which together account for about 10% of the Dutch population. To date, >70,000 people have responded to the questionnaires at least once, and the questionnaire program is still ongoing. Data collected by the questionnaires will be used to address four aspects of the outbreak: (1) how the COVID-19 pandemic developed in the three northern provinces of the Netherlands, (2) which environmental risk factors predict disease susceptibility and severity, (3) which genetic risk factors predict disease susceptibility and severity and (4) what are the psychological and societal impacts of the crisis.