Theanine didn't do anything for me.
Amino acid therapy on correct dosing helped my depression, brain fog, low energy / sleepiness and anxiety on a profound level.
On bad doses however both got a lot worse. That was mostly from too high a dose. The doctors that pioneered it recommend not exceeding 1500mg tyrosine twice a day, I went up to 4500 as per one of their therapeutic doses.
It's basically daily:
1500mg tyrosine
150mg 5-htp (always a 10-1 balance)
(once morning and once night)
2500 mg L-cysteine up to 4500 daily.
then you need to take vitamin b6, folate, calcium and selenium as cofactors, I just take a multi with enough to equal out.
If you want to know exact dosing you can look up "cysreplete" and "neuroreplete" pills and see the contents. Dosing is equal to 2 neuroreplete and 3 cystreplete daily.