Amphetamine stimulants are very very addictive, with physical dependence symptoms. If you take them in moderate doses regularly and then stop, you will feel like you're going to DIE. Be very very careful using them, always limit your dose. If you ever feel like you "need" them to game, it's time to stop taking them completely.
Caffeine and Ephedrine also have these issues (talk to anyone that drinks coffee every morning, about how their day is if they don't get any), but to a lesser extent.
MDMA, if taken more regularly than every few months, is neurotoxic. Although there is probably some dose dependency going on, and low dose MDMA would very likely remove ANY social anxiety.
Caffeine and Ephedrine also have these issues (talk to anyone that drinks coffee every morning, about how their day is if they don't get any), but to a lesser extent.
MDMA, if taken more regularly than every few months, is neurotoxic. Although there is probably some dose dependency going on, and low dose MDMA would very likely remove ANY social anxiety.