^It's not as simple as that. I find that GHB and alcohol actually keep me awake, even thought they're definitely downers. I yawn and want to sit down on MDMA, though it's obviously an amphetamine. So, I do find GHB stimulating (in a phenomenological sense), even though it's a depressant (in a pharmacological sense). I think that you're equivocating, in the same way that people think that depressants make you depressed.
I never understood how any opioid can have "upper" effects. Yeah, I get that some opioids are more sedative than others, but none have any stimulatory effects - not even oxycodone. They are all CNS depressants and cause respiratory depression, among other side effects which are "downer" in nature.
kokaino, that wasn't really my point, what I was getting at is that "stimulating" in the sense it is being used in this thread doesn't mean "having the action of a stimulant". Hiking and climbing and cycling are stimulating, but they're not stimulants.