Hello, Doctors. I Have A 14 Year Old Daughter Who

Hello, Doctors. I have a 14 year old daughter who is mentally delayed. She has been experiencing what she calls "voices" in her head which i believe are racing thoughts and anxiety since January of this year. She is seeing a therapist once a week and the psychiatrist has her on Prozac. Her anxiety levels are back to normal, but the "voices" or racing thoughts isn't getting better. She is unfocused, fearful and unable to do normal everyday things like putting her clothes away, finding things, even eating seems to be a chore. What treatment would you recommend. What meds would help her get her thoughts under control? Thanks. YYYY@YYYY .