Twitter Anxiety around COVID19 in France

The lines indicate the following events:

Purple: Notre Dame on Fire no 2019-04-15
Green: First Covid19 case on 2020-01-24
Orange: First death from Covid 19 on 2020-02-14
Turquois: Measures
- Light: Ban of public events on 2020-02-29
- Dark: Nationwide social distancing measures on 2020-03-15

Methods:

We analysed 352 million tweets from users located in France by Crimson Hexagon. Only original tweets (no retweets) in French and from users with a number of followers between 100 and 100.000 (to remove spam and media)
Tweet text is matched for anxiety terms from the LIWC lexicon. LIWC is a standard methodology in psychology for text analysis that includes validated lexica in French.
Marked dates during the Covid-19 outbreak are taken from Wikipedia.

A typical day in France shows a frequency of anxiety terms in Twitter of about 4.9%.
The highest peak since January 2019 has been the fire of Notre Dame in Paris, with about 6.3% of tweets containing anxiety-related terms.
The peaks that coincide with the ban of public events and the start of nationwide social distancing measures to slow down the outbreak of Covid-19 are almost as high, with about 5.8%.
In comparison to a typical day, this corresponds to an increase of about 1% compared to an average day.
As in many other countries, the least anxiety is expressed during Christmas and New Years eve.

With the exception of the fire of Notre Dame, the peaks that have occurred since the outbreak of Covid-19 have led to the highest peaks of anxiety and worries expressed in tweets in France. Whereas, the first case and first death did apparently not receive enough attention to influence anxiety on twitter, measures taken to slow down the spread have done so. This makes sense, given they concern people more directly.
While this increase of about 1.4% is not negligible, it also shows that Twitter is far from being dominated by anxiety. The expression of other emotions and willingness to help may have changed as well.