The dysphoria of feeling like you're in the wrong body is the mental illness, there currently is no fix for this except for transition. All outcomes improve by

The dysphoria of feeling like you're in the wrong body is the mental illness, there currently is no fix for this except for transition. All outcomes improve by social transition with family support, notably outcomes do not improve by telling transgender people that they're mentally ill and that they must accept their gender assigned at birth. Being transgender alone does not constitute a mental health condition. Dysphoria is the culprit. If people could transition at will The Culture style there would be zero confusion on this point.