I can only share my own personal experience with 5HTP. I was going through adrenal fatigue and a very dark Depression at the time when something in me felt like my neurotransmitters were low, specifically seratonin. I was crying at the drop of a hat and felt as if my world was caving in on me. I went out and bought a bottle of now 5HTP 200mg. I opened up the capsule and held it under my tongue for almost an hour. Within a couple of hours I was able to go out to eat with my wife and even a smile a bit. The difference was like night and day for me. This supplement will not help everyone with Depression but it will most likely help those whose Depression is a result of low seratonin.
I have taken Dopa Mucuna which is a dopamine enhancer. it seems to increase my craving for fun foods pizza, hamburgers, donuts, all the stuff I shouldn't be eating. It is helpful for boosting testosterone as well. I take Muncuna caps when I feel the need for them. My favorite mood enhancing supplement is SAM-E. Literally makes me laugh at my own thoughts/jokes. A great overall mood lifter. You just have to take enough of it to make a difference which can be as much as 800mg which can get expensive.