The pandemic is creeping into people's nightmares, according to a Finnish study that was published this week.
Hundreds of volunteers told their dreams to Helsinki University scientists during a Covid-19 lockdown earlier this year.
Dreams of lost passports, closed borders, overcrowded spaces and death came up again and again in these reports.
Handshakes or hugs also became the stuff of nightmares. Sleepers experienced them as an inappropriate violation of social distancing rules in their dreams.
"Usually, dreaming is a really private thing. But when the environment is changing so quickly in such a short time, many people seem to have shared associations," lead author and psychologist Anu-Katriina Pesonen told.
Her team used an algorithm to group dream topics into categories and found that a third of these categories were clearly linked to the pandemic.
The study that was published in the journal "Frontiers in Psychology" also used sleep-pattern reports from 4,000 Finns.
More frequent nightmares
More than a quarter of them reported more frequent nightmares than before the pandemic, and around a third of them woke up more frequently during the night.
However, more than half of the respondents slept longer than usual, partly because more people were working from home.
Scientists who were not involved in the study said that the Finnish results should not be viewed as generally valid.
Austrian psychologist and dream expert Brigitte Holzinger cautioned that the Finnish nightmare figures seemed "very, very high," even though the overall results are in line with her own, still unpublished research into Covid-19 dreams.