They are both about a main character who is hesitant in a way with accepting the other psychic. Both main characters have a large out put of power and both are called categorized by a zero, both main characters are protective over their friends, but in zero the main character isn't as trusting or forgiving.
Each individual in psycho busters have a different psychic power, while in zero it's only 3 categories, and they use a lot of power that are seen iin psycho busters.