Explaining early theories about mental disorders, Advanced Placement Psychology teacher Kristen Crandall shows her class a picture of a skull with a hole drilled in it on Wednesday, April 20. According to Crandall, before people understood mental illnesses, they thought there was an evil spirit trapped in a person. In order to expel the evil spirit, they would drill or burn holes into a mentally ill person's head. “I think it’s important for students to understand that when we do talk about treatments that are used today just how new those actually are,” Crandall said. “They make so much sense when you look at them but I think in order to appreciate them, you have to understand how far the world of psychology has come.”