An earlier ruling heard how unit staff had witnessed “a profoundly disturbing and distressing scene when X self-harmed by repeatedly banging her head and face against the wall”.
Staff said she must be checked every 50 seconds when she is in the shower.
The unit has said 13 young people who were also being detained at the centre complained the quality of the care they were receiving was “in breach of their statutory rights” because staff had to attend to X and had less time to organise activities for them.
Following the latest ruling, the judge said X should not be “privileged” because her case came before a senior judge.
He added: “I emphasise this because a mass of informed, if anecdotal, opinion indicates that X’s is not an isolated case and that there are far too many young women in similar predicaments. How are they to be protected?”
Sir James said the publication of his judgment last Thursday had “prompted substantial coverage”, with his “blood on our hands” warning making front pages.