Can stress cause hair greying, or is it a myth? - Stem cells may have something to do with it-
Channel: Biochemistry Explained
Date: 2020-07-13

It is often cited as being true, but can stress actually make you look older? Researchers from Harvard University have now provided proof for this ‘myth’. They first showed that stress caused hair greying in mice, after which they ruled out a variety of mechanisms involved in this process. Noradrenaline appeared the key player in hair greying via its release by the sympathetic nervous system as part of the fight-or-flight response. 

The paper I discussed can be found here (including all the figures):
https://www.nature.com/articles/s41586-020-1935-3