About 2 years ago I had a bizzare reaction to skim milk in which it seemingly cured my POIS for ~2 months. It was unreal, it didn't feel like a drugged state but I had no pain, no fatigue, and my intellectual ability sky-rocketed. I still had normal emotional shifts so it wasn't a manic episode. It was great to feel how healthy people feel for a change and made me aware that it was possible for me to feel healthy I just have to find the key. Lately I thought it might have been an abnormal reaction of my body to milk opoid peptides, but that wouldn't explain the resolved cognition and fatigue.
However now milk doesn't affect me at all except for making me slightly sleepy so I drink it before bed to get to sleep easier.