The Pathfinder version of Psychic Reformation removes the XP cost that was present in the 3.5 version, and replaces it with a sort of pseudo-negative level cost instead. One part of this cost is that, if a character makes changes to levels lower than their last, they have their current and max hit points reduced by 5 per level difference.
If a character has less that 5 hit points per level, can a Psychic Reformation kill them? For example, a Wizard with a 12 Con will only have 4.5 hit points per level. If a Psychic Reformation is used on this wizard to change all of his levels, will the wizard be stuck at negative maximum hit points?