Dreaming during the Covid-19 pandemic: Computational assessment of dream reports reveals mental suffering associated with negative feelings and contagion fear

Neuroscience and psychology agree that dreaming helps to cope with negative emotions and learn from experience. The current global threat related to the COVID-19 pandemic led to widespread social isolation. How does this situation affect dreams? Is dreaming during the pandemic related to mental suffering? Does the act of observing dreams help to mitigate mental suffering? To address these questions, we applied natural language processing tools to study 210 dream reports (n=67, Pandemic group n=42, plus control group balanced for age, sex and education) either before the Covid-19 outbreak or during March-April, 2020, following the pandemic announcement by the WHO and quarantine was imposed in Brazil. Post-announcement dreams showed a higher proportion of words related to anger and sadness, and higher average semantic similarities to the terms contamination and cleanness, which tended to increase over time. These features were associated with mental suffering related to social isolation, as they explained 39% of the variance in PANSS negative subscale (p=0.0092). Besides, dream observation was positively self-evaluated and dream similarities to contamination and cleanness revealed different impacts of the dream observation effect. These results corroborate the hypothesis that pandemic dreams reflect mental suffering, fear of contagion, and important changes in daily habits.