There's a study here which shows, quite surprisingly, that Choline blocks the a3b4 nicotinic receptor in a similar fashion to conventional antagonist Hexamethonium:
https://isccb12.webs...al/38-Rubio.pdf
I suspect this receptor has a part to play in depression, because another drug, Mecamylamine, has been shown in numerous studies to have anti-depressive effects, as well as attenuating effects of stress hormones:
https://www.ncbi.nlm...pubmed/19404193
https://www.ncbi.nlm...pubmed/25315361
https://www.ncbi.nlm...pubmed/18480694
https://www.ncbi.nlm...pubmed/19874251
From what I've read, The a3b4 receptor is a key target of Mecamylamine, the other being the a4b2 receptor.
So am I onto something or am I talking a load of blarney?
Bear in mind, supplement companies typically sell choline in combination with another compound called Inositol, which has demonstrated anti-depressive effects also (I believe levels are too high when a person experiences mania).