Gender Dysphoria might be a disorder, but the treatment for adults is what? Does making them cisgender work?
It looks like it's unknown if it is a biological or mental disorder. Evidence points to the former, that gender identity forms in the womb.
Gender Dysphoria in children is evidently separate issue and there is disagreement about treatment.
That's based on what I am reading.
Edit: cross dressing is diverse gender expression, not considered a disorder.
Feeling like a woman trapped in male body and being okay with it is diverse gender identity, not considered a disorder.