Add a few microgrammes of Vitamin D, and at least you’ll be able to rule out vitamin deprivation.
I was shocked to learn that most British people get all of their dietary vitamin C, not from fruit, but from the more humble potato. Low in vit.C, but we eat loads of spuds. Distortion!
Microbiome diversity might be another factor to look into?, serotonin , dopamine etc are complicated, and having the right amount, in the right place, at the right time, does need study.