ABSTRACT
Objectives: There has been much concern about the impact of the COVID-19 pandemic and associated social restrictions on adolescent health. The aim of the present study was to compare symptoms and prevalence rates of insomnia, anxiety and depression between prepandemic times and the initial phase of the COVID-19 pandemic, in a large sample of Norwegian adolescents. Method(s): The longitudinal survey was conducted in a large sample of high school students (16-17 years old), and included the Bergen Insomnia Scale (BIS), the General Anxiety Disorder-7 (GAD-7) and the Patient Health Questionnaire-9 (PHQ-9). Wave 1 was conducted in spring 2019 and wave 2 in spring 2020, during the last 10 days of a 60-day long, COVID-19-related, school lockdown period. A total of 2249 students responded in both survey waves, representing 60.2% of the invited cohort. Statistical analyses included paired-samples ttests and McNemar's tests, the latter with dichotomous proxies of insomnia disorder (based on BIS) and anxiety/depression (GAD-7/ PHQ-9 scores >=10, indicating moderate to severe symptom levels) as dependent variables. Result(s): The BIS score was slightly reduced from 12.3 +/- 8.4 in 2019 to 11.9 +/- 8.2 in 2020 (p = 0.028), but the prevalence rate for insomnia remained stable (33.4% vs. 33.6%, p = 0.896). Similarly, the GAD-7 score was reduced from 5.9 +/- 4.9 in 2019 to 5.6 +/- 4.6 in 2020 (p = 0.014), but the prevalence rate for anxiety remained unchanged (19.8% vs. 18.7%, p = 0.316). The PHQ-9 score increased from 7.5 +/- 5.7 in 2019 to 7.9 +/- 5.6 in 2020 (p < 0.001), and the prevalence rate for depression increased accordingly (28.7% vs. 32.1%, p = 0.002). Conclusion(s): The prevalence of depression amongst Norwegian high school students increased during the initial phase of the COVID-19 pandemic compared to pre-pandemic times, whereas prevalence rates for insomnia and anxiety remained unchanged. More longitudinal research is needed to increase our understanding of the effect of the COVID-19 pandemic and associated social restrictions on adolescent sleep and mental health.