Dragons Psionics

ok I am recently exploring the Psionics handbooks and notice that the spell Ego whip does a 1d6 Cha damage. when the CHA hits 0 what all effects can take place? My idea on the CHA going to 0 is the PC goes into a stupor and collapses. be it depression or self disillusion i'm not sure the player can think of something he feels his character would do but my over all idea is fair for now i would like some input on this i know in some rules if a wis score goes to 0 the player dies or fades away from lack of self realization the character no longer thinks he or she is real. or so i've come to think of the rule. hehe. but i find the charisma is a almost pointless score so how would that work out. (i know the cha score determines a lot for certain classes but in the overall makeup i find it pointless. so my knowledge is most likely way too Limited on how i perceive this score input is what i'm after and if learning the score is important then by god teach away.)