The girlfriend/CF diet has been a miracle in my house.
My difficult child 1 used to be diagnosis'ed with Depression and ODD. She was taking the highest dose of Lexapro and we were about to add an antipsychotic to hopefully eliminate the violence. Instead, we discovered she needed to be gluten and casein free and since I had read that could affect behaviour and mood, we waited to see what happened with the diet change.
She is now medication free and usually a pleasure to be around, even though she is a teenager now. She does sometimes cheat on her diet and then still has that old behaviour.
I also went gluten free and had symptoms go away that I didn't know I had. Brain fog, ADD-like symptoms, auditory processing problems, anxiety, fatigue, and more.
Mark Hyman, MD wrote a book called "The Ultra Mind Solution" which has many different diet changes and supplement suggestions to help with mood.