Joon's (
Mary Stuart Masterson) exhibited symptoms are suggestive of several disorders. She may be schizophrenic, since Benny (
Aidan Quinn) tells Sam (
Johnny Depp) that she often hears voices. Since Benny also says that she has very specific routines that should not be interfered with, she may have Asperger's disorder, similar to autism or an obsessive-compulsive disorder in which routines and behaviors are done to ward off anxiety. This would explain her need for rigid structure. Since Benny and Joon were at their parents' death scene from a car accident, she may have post-traumatic stress disorder (PTSD). She wore a helmet when she rode in Benny's car and is very sensitive to noise.