I'd say mental.  Physical is something that can heal over time (and some argue mental heals over time as well).  There may be a physical scar, but you may not remember what the pain felt like (other than it hurt like a son of a bitch).  Mental pain can be described to a T.  I bet if anyone has mental scaring, they can tell you exactly what it is from and how it made them feel.  Often times, mental pain changes a person comletely, even if it is only for a period of time.     
Of course.. all of your perspective depends on how well of a pain tolerance you have, and how good of a mental tolerance (self-esteem) you have as well.   
Just a tad of my .02