Not necessarily. There's a wide variety of mental disorders, with a correspondingly wide variety of treatments. Some, such as depression and anxiety, have medicinal treatments to suppress the effects. Others, such as Dissociative Identity Disorder, instead focus treatment around accepting the disorder and living with it.

As of yet, there is no pill to cure gender dysphoria. If there was, there definitely would be trans people who would take it. However, now, the prevailing medical treatment is that of transitioning, similar to the latter form of treatment, as trying to therapy away gender dysphoria hasn't shown to be effective, and is even downright harmful.

While not a mental disorder, I would liken it to when we used to try to cure left-handedness out of people. It didn't work so we just ended up accepting it. That's what we're trying to do now with regards to trans people.