JH produces a large literature review of the research on suicidality and LGBTQ+ populations.
Ann P. Haas, Mickey Eliason, Vickie M. Mays, Robin M. Mathy, Susan D. Cochran, Anthony R. D'Augelli, Morton M. Silverman et al. "Suicide and suicide risk in lesbian, gay, bisexual, and transgender populations: Review and recommendations." Journal of Homosexuality 58, no. 1 (2010): 10-51
"Because death records do not routinely include the deceased person's sexual orientation, there is no official or generally reliable way to determine rates of completed suicide in LGB people."