Psycho

Psycho is a drug in the Fallout series.

Background
Psycho appears as a form of injected drug composed of strange, unknown chemicals of military origin, that comes with its own unique delivery system. It was designed at the orders of General Chase specifically for military use. It increases a soldier's damage resistance, and its dampening effect on higher brain functions make for tough, but uncontrollable, troops. This drug was very popular for human-wave assaults. 

Psycho


Depending on the game, Psycho will give different effects. For Fallout 1 and 2, Psycho will increase damage resistance, allowing subjects to survive hits more easily. For Fallout 3 and Fallout: New Vegas, Psycho will increase the damage dealt with weapons. In the latter game, the Psycho drug is an ingredient for the Slasher drug. In Fallout 4, all Psycho acts like Slasher did, boosting Damage Resistance as well as Damage.

Slasher


Slasher is a chem which combines the effects of Med-X and Psycho into a single drug. It is possible to combine the effects of this drug with Med-X to gain a 50% boost to damage resistance. It will not stack with Psycho.

Psycho jet


Psychojet, like Slasher, combines two chems, Psycho and Jet, and has the same effects.