http://www.stat.ucla.edu/~cochran/pdf/MentalHealthDiscrimLGBinUS.pdf
http://www2.psych.ubc.ca/~schaller/Psyc591Readings/Fiske2000.pdf
http://www.npc.umich.edu/publications/workingpaper06/paper11/working_paper06-11.pdf
Sorry about that, shouldn't have been so lazy and only used anecdotes. ^^