By Peter Dizikes 

The Covid-19 pandemic has been depressing, demoralizing, and stressful for people around the world. But is there any way to measure exactly how bad it has made everyone feel?

A new study led by MIT researchers attempts just that, through a massive examination of hundreds of millions social media posts in about 100 countries. The research, which analyzes the language terms used in social media, finds a pronounced drop in positive public sentiment after the pandemic set in during early 2020 — with a subsequent, incremental, halting return to prepandemic status.

To put that downturn in perspective, consider a prepandemic fact that the same kind of analysis uncovered: Typically, people express the most upbeat emotions on social media on weekends, and the most negative ones on Monday. Worldwide, the onset of the pandemic induced a negative turn in sentiment 4.7 times as large as the traditional weekend-Monday gap. Thus the early pandemic months were like a really, really bad Monday, on aggregate, globally, for social media users.