Cool.

There is this bit from this study:

Treatment options for patients with gender identity at variance with physical appearance can be evaluated in the order of extent of invasiveness. The least invasive intervention would be counseling such patients to accept the circumstance. As already noted, however, no available data support the success of such therapy. The next least invasive approach might be a targeted treatment of the underlying problem. The medical community, however, has little knowledge about the brain region associated with gender identity, and even less is known about techniques for manipulating it.

And this one: (full PDF is here and is interesting... man I've been out of school for too long)

The observations that psychotherapy is not helpful in altering a crystallized cross-gender identity and that certain transsexuals do not show severe psychopathology has led clinicians to adopt sex reassignment as a treatment option.

To show the benefits of transitioning:

This study shows quality of life increasing for FtM people with hormone treatment compared to without hormones, and this one shows increasing quality of life for MtF people as a result of surgery. This one and this one show low to no regrets from people who have gone through sex reassignment surgery.

I guess I didn't have the sources on hand that I thought I did for the first part of my point #2 (effects of gender dysphoria), so I probably got that more from reading individuals experiences, eg. on reddit or blogs.