How do you know this? Where have the statistics ever been reported on this?
Is there genital contact? Is there oral/genital contact? Are there multiple partners? If so, then there are STD's involved. I've not seen studies, just news stories. Lesbians also have the drug and alcohol problems that homosexual men have. I know this because my b-i-l has learned this from law enforcement officers who deal with the domestic violence in these 'relationships' every day.