Deterioration of sleep and mental health in individuals with insomnia during South Africa’s COVID-19 lockdown

Sleep and mental health difficulties have been observed in response to COVID-19 pandemic-induced lockdowns, but few studies have described the impact of lockdown on individuals with self-reported insomnia. The purpose of this study was to compare the impact of lockdown on changes in symptoms of insomnia, depression and anxiety between persons with and without self-identified insomnia. In total, 1048 adult participants from the general South African population took part in this retrospective observational study during Alert Levels 4 and 3 in May and June 2020. They completed an online survey assessing current and past self-reported sleep disorders. Symptom profiles of insomnia (Insomnia Severity Index), depression (Patient Health Questionnaire-2) and anxiety (Generalised Anxiety Disorder 7-item scale) were assessed immediately before and during a 5-week lockdown (March–April 2020). Comparative analyses were conducted between participants who identified a current or previous diagnosis of insomnia (n = 135, Insomnia group, irrespective of whether they had current symptoms or not) and those reporting no sleep disorders (n = 700, No-Insomnia group). Participants who reported multiple sleep disorders were excluded from the analyses (n = 213). Symptoms of insomnia (p < 0.001), depression (p = 0.001) and anxiety (p = 0.001) worsened in all participants during lockdown compared to pre-lockdown measures. Time-by-group interaction effects were observed for all measures (p < 0.001) such that the Insomnia group reported larger increases in insomnia (p < 0.001), depression (p < 0.001) and anxiety (p < 0.001) scores compared to the No-Insomnia group during lockdown. Participants with self-reported insomnia, even if currently asymptomatic, were more vulnerable to worsening insomnia and depressive and anxiety-related symptoms during lockdown compared to those with no insomnia. This highlights vulnerability to mental-health-altering situations in individuals with self-identified insomnia, and thus the necessity to provide mental health support for this patient population.