[member="Harley"] The closest things to curses I could cast would be Force-horror (which causes the target(s) to be frightened of the caster), Force-roadblock (which closes off a memory from being consciously accessed even though it is otherwise preserved), Force-refraction (which could cause a target to be transparent, among other things - it can be a boon if temporary but a curse if permanent)
Most of my uses of spells are short-term, however.