Really, it comes down to how mean everyone is being, and how suicidal they are. You know how to make this stuff but you just want to mess with people's heads instead of sharing the goods? If even one psychic decides you're more of a threat alive than dead, you are so dead. A long range rifle can take someone out, or explosive traps, or just trading for a favor from a warlord.

I'm sure this stuff is written down somewhere, the recipes and such. Or perhaps you can make it with your mind.

As for drug effects, there's hypnotic drugs that put you into a state where you can be ordered around, given triggers and so forth, and those triggers might last for months or years, long after the drug has worn off. Sometimes the drug is just the stepping stone to what you want, and it doesn't actually have to be in the persons system to work for you.

Smoke
Blood
Approaching Storm Clouds
Bullet Ricochet (or someone nearby is hit)
Sparks
An Explosion
A Scream