If I recall, the median age of those entered into that study were over 18? They're hardly children. There are far more studies published by authors who are not members of organisations formed to prevent trans people from accessing treatment. The studies tend to ask trans youth and their families directly whether children are happy, adjusting and thriving rather than fold contextless numbers together to manufacture a crisis in mental health.
But, you asked about concern about the mental health of trans children. I am really concerned that they are being harmed by the absence of healthcare access in this country. I am concerned that they have been excluded from care because there is a larger cohort of non-trans children who have requested and received trans-oriented treatments that should not be receiving treatment. Some of these children ultimately detransition, others will presumably be living as the opposite sex for the remainder of their lives.
As far as I know, living life as the opposite sex and growing old is not currently illegal in this country, as much as some have made realising the goal their life's focus. It's not a death sentence. It's not a horrible existence. And no, it is not impossible.
Males who received treatment to become females were psychologically healthier than all other cohorts entering the study, according to the framing.
The clinic I was in did not provide psychologic support services either.
If I apply the protocol to myself, I would have increased the morbidity numbers because I saw a psychiatrist for a number of things after my rape. I knew others who saw people for depression and develop coping skills while they were dealing with hate and abuse. 60.7% is a really big number, but it is wrapped with no further information.
The study authors didn't address the categories of morbidity at all or the number of visits to a psychologist made, and yet they had access to all the data. Not all morbidities would preclude entering into gender treatment. Were those same morbidities excluded in the post-treatment morbidity triggers? No one knows.
So yes, OP. I am really concerned. I'm concerned about health of children and adolescents who have the right to treatment from clinical experts who are currently prevented from accessing care by political legislation influenced by the lobbying efforts of religious conservatives, political conservatives and a few women, who latched on to a culture war that diverts focus from actual issues impacting women.