England’s National Health Service (NHS) joined other European nations in reversing policies regarding the treatment of children who say they feel like they are the opposite sex. That’s a classified mental illness known as “gender dysphoria.”

Under the new policy, children treated at NHS clinics will not be allowed to be prescribed puberty blockers.

An exception to the ban will be children enrolled in UK government clinical trials.

“Puberty suppressing hormones (PSH) are not available as a routine commissioning treatment option for treatment of children and young people who have gender incongruence/gender dysphoria,” writes the NHS. “We have concluded that there is not enough evidence to support the safety or clinical effectiveness of PSH to make the treatment routinely available at this time.”