perm damage vs highlighting damage

I have a question. Which is worse on your hair--perming your hair or highlighting your hair? I have a friend who highlights her own hair every 8 weeks. When her roots start showing really badly, she will get a bottle of deposit only color and dye it back to her natural hair color. Then she pulls her hair through a cap and puts on the highlighting bleach. Then she tones it to the correct color of blond. She does this because she says she tried doing her roots one time and it was a disaster. Apparently she got them too light and she looked like a reverse skunk. I told her that her hair was going to fall out, but she said what she was doing was not worse than someone who gets a perm in their hair every 2 to 3 months. What do you think?