Fentanyl factor did not start in March of 2020.
https://www.nbcnews.com/politics/immigration/fentanyl-seizur...
Specially if you consider that the overdose deaths did not suddenly appear in 2020.
Have a look at the picture on this page to see how much lethal it is : https://www.bioonesantaclarita.com/biohazard-and-crime-scene...
In teenagers this has already caused a spike in mental illnesses.