Well, looking at
Wikipedia on gay marriage, there was a section talking about mental health, and the four sources cited are:
^ Price, M. "UPFRONT — Research uncovers the stress created by same-sex marriage bans" in Monitor on Psychology, Volume 40, No. 1, page 10, January 2009. Washington DC: American Psychological Association. [3]
^ Potoczniak, Daniel J.; Aldea, Mirela A.; DeBlaere, Cirleen"Ego identity, social anxiety, social support, and self​-​concealment in lesbian, gay, and bisexual individuals." Journal of Counseling Psychology, Vol 54(4), October 2007, 447–457.
^ Balsam, Kimberly F.; Mohr, Jonathan J. "Adaptation to sexual orientation stigma: A comparison of bisexual and lesbian/gay adults." Journal of Counseling Psychology, Vol 54(3), July 2007, 306–319.
^ Columbia University's Mailman School of Public Health: Lesbian, gay, bisexual individuals risk psychiatric disorders from discriminatory policies
Those aren't links, so I have no idea how handy they are. They didn't have a section saying that gay parents raise their kids goodright, but they do talk about all the negatives stemming from how they're treated and not because they're wrongbad.