[plusminusplus]

...in the 169 rats that were part of the study.

It further concludes:

> High doses of nicotine or repeated exposure may also promote anxiety (citing 3 studies)

> low doses of nicotine have a similar effect to decrease anxiety behaviours [...] whereas high doses of nicotine promote anxiety behaviours

[vorpalhex]

Most drugs are dose dependent.

The effects of nicotine as an anxiolytic are well known:

https://pubmed.ncbi.nlm.nih.gov/12151749/

Rat studies to find dose limits are a valid case for rat studies.