as someone who cannot touch yellow-5 or tartrazine I know from my childhood the effects this can have and sadly as an adult I still cannot go anywhere near the stuff as it has almost personality altering effects in me. It took years to find the cause when I was young for my horrifying behaviour to be stopped and thankfully it was banned in England shortly after. Only had a few episodes in the past 30 years because something slipped the net but quickly found.