This information comes from website “Catholic Answers”.  Information sources are cited at the end of this document and are noted in blue font.

“Marriage, is a major public health issue and not just a private affair. Marriages that are exclusive, permanent, unconditional, and life-giving contribute much to public health and longevity; marriages that fail any of these criteria and end in divorce create an enormous social, emotional, and health care burden for the couple, their children, and society.”

Legalizing same-sex marriage would indirectly promote/endorse homosexuality.  Given the statistics below, such promotion/endorsement by the state is irresponsible and harmful.

• 14 times more likely to attempt
• 3½ times more likely to be successful 48
• Thirty years ago, this propensity toward suicide was attributed to social rejection, but the numbers have remained largely stable since then despite far greater public acceptance than existed in 1973.

• Study after study shows that male and female homosexuals have much higher rates of interpersonal maladjustment, depression, conduct disorder, childhood abuse (both sexual and violent), domestic violence, alcohol or drug abuse, anxiety, and dependency on psychiatric care than heterosexuals.49
• Homosexuals of both sexes have high rates of drug abuse, including cocaine, marijuana, LSD and other psychedelics, barbiturates, and amyl nitrate.54
• Lesbians share male homosexuals' propensity for drug abuse, psychiatric disorder, and suicide.58

• Life expectancy of homosexual men was only forty-eight years before the AIDS virus came on the scene, and it is now down to thirty-eight.50
• Only 2 percent of homosexual men live past age sixty-five.51

• MEN: anal cancer, which is almost unheard-of in male heterosexuals

Sexually transmitted diseases, including urethritis, laryngitis, prostatitis, hepatitis A and B, syphilis, gonorrhea, chlamydia, herpes, and human papilloma virus, which also causes genital cancers).52

• WOMEN: Lesbians are at lower risk for STDs but at high risk for breast cancer.53

Footnotes:
48. R. A. Garofalo et al., "The Associations Between Health Risk Behaviors and Sexual Orientation Among a School-Based Sample of Adolescents," Pediatrics 101 (1998): 895-902.
49. R. Herrell et al., Archives of General Psychiatry 56 (1999): 867-74; D. M. Fergusson, J. Horwood, A. L. Beautrais, "Is Sexual Orientation Related to Mental Health Problems and Suicidality in Young People?" Archives of General Psychiatry 56 (1999): 876-80; M. J. Bailey, "Homosexuality and Mental Illness," Archives of General Psychiatry 56 (1999): 883-4.
50. P. Cameron and K. Cameron, "Homosexual Parents," Adolescence 31 (1996): 757-76.
51. Ibid.
52. Laura Dean et al., "Lesbian, Gay, Bisexual and Transgender Health: Findings and Concerns," Journal of the Gay and Lesbian Medical Association 4, no. 3 (2000): 101-51.
53. Ibid.
54. Ibid.