I used to have military-grade irritability when I first developed ME/CFS. It was really severe, and I had to bite my lip all the time. So I was always looking for treatments, and trying to figure out what would trigger it, because it is such an unpleasant mental state.
Apart from amisulpride, I found the following reduce my irritability:
Estriol 0.3 mg (as a transdermal cream on my arms) I found improves irritability, sociability, and boosts mood a bit within a few hours. Though as a male I can't use it all the time, as you would start growing breasts. I originally experimented with estriol as it is a weak oestrogen which has anti-autoimmune effects, and has been used as an MS treatment. I found no benefits for my ME/CFS, but noticed it was good for irritability.
Arginine 10 grams daily.
Vitamin B2 50 mg.
N-acetyl-cysteine I read is sometimes used to treat the severe irritability found in autistic children, though I have not tested this for my own irritability symptoms.
Occasionally I also get anger flair ups (for no external reason, just due to aberrant brain chemistry), and would spend the whole day in an angry mood, which I don't find pleasant at all. Anger I find is similar to irritability, but there is more emotional weight behind anger.
It took me many years to find a solution, but I discovered that supplements which suppress testosterone, and suppress dihydrotestosterone (DHT), actually work very well to calm the anger, and work within a few hours.
So my usual anti-anger protocol is: saw palmetto (standardised extract) 320 mg, peppermint oil 200 mg and zinc 25 mg. These all lower testosterone or DHT, and clear my anger within a few hours.
