Shocking art movement has a following — I'm not sure about it on reflection (9)

I believe the answer is:

traumatic

But I can't explain it at all!

(Other definitions for traumatic that I've seen before include "Psychologically damaging" , "Direly shocking" , "Deeply distressing" , "Emotionally shocking" , "Psychologically painful" .)

I've seen this clue in The Guardian.

Want a hint initially instead of a full solution? Install my app