I was addicted to ultram I called it Tremadol. It's suppose to have mild SSRI like effects. As I remember they kinda made me hyper more so then vicoden.

Anyway I've read the endorphin system is the first line of defense against stress when it's depleted the body uses serotonin then GABA. I wouldn't mind it being studied other then addiction and abuse it's pretty easy on the body.