How would the nurse best explain that the care Jessica will receive at the psychiatric   facility is based on evidence?

CHAPTER 4, Evidence-Based Practice
In completing the case study, students will be addressing the following learning objective:
Define evidence-based care.
1. Jessica, a 17-year-old girl who came with her family from Romania to the United States 10 years ago, is brought to the mental health clinic by her mother.  At the admission psychiatric interview, the mother stated that Jessica has been saying for 6 months that aliens have been conducting experiments on her and will soon take her in a spaceship to their planet.  Jessica is often awake at night and roams the house with a hammer and sharp knife, searching for aliens. Jessica’s mother says that she fears that some night Jessica will harm a family member whom she believes to be an alien.  The mother then said that she did not bring Jessica for psychiatric care earlier because she had heard that much of mental health treatment was quackery and a waste of money. The psychiatric nurse explains to Jessica’s mother that all mental health treatment is based on scientific principles.
(Learning Objective: 3)
a. How would the nurse best explain that the care Jessica will receive at the psychiatric   facility is based on evidence? Give two examples of psychiatric evidence-based care, and explain the scientific evidence that supports your examples.
Case Study, Mohr