What is Leah's disease in the ''bronze bow''?

Leah is not possessed by demons, she is just scared because she lost alot! Like her brother Daniel left her and both of her parents died to the Romans. so she has gone through alot. Thacia has helped her, but Daniel ruined his relationship with Leah torwards to the end. However they are good again. Leah has trust issues and does not like to be left alone and stuff....