Psychotic difficulty is the same as Insane difficulty, except you will only have one life. It's strongly advised that you practice these levels on Insane difficulty first and take advantage of uploading your save data or copying it to a USB drive or via PSN cloud saving after each level to make life that little bit easier. It requires knowledge on specific areas, especially boss battles which can be incredibly frustrating to fail at as they're usually located at the end of the level.

Make sure you have the right gun for the situation and try different tactics out. A good example of this is holding on to the rocket/explosive pistols in the Mines of Death in one hand until reaching the two fast moving mini bosses, taking them out with one shot. Remember practice makes perfect, try playing on Insane difficulty and picking up collectibles and doing it straight after to keep it fresh in your mind. Another tip is to use move controllers as they allow for greater precision. Don't bother with your score/multiplier, save the ammo for when you need it.

Look to the silver killer trophies for further tips and tricks on boss battles:

•  ​Haunted Lodge killer
•  Nightmare Descent killer
•  Hotel Hell killer
•  Psycho Cellblock killer
•  Ghost Town killer
•  Mines of Death killer
•  Final Inferno killer