I don't have personal experience with this but a good friend of DD's was put on Prozac earlier this year at the age of 7. It was a huge help. She was in a very, very dark place and was on homebound the last couple of months of last school year. Talk/play therapy was not enough for her but the Prozac made all the difference. We just saw them yesterday and she seems basically back to her old self. Her mother said they have now removed all the supports that were in place to transition her back to school. I think she will probably always be an anxious kid but she is no longer crippled by it.

Good luck!