From The Harvard Mental Health Letter

A study of a large representative sample of the popu- lation of the Netherlands indicates that homosexual men and women have a higher than average rate of most psychiatric disorders …. To avoid ambiguity about sexual orientation, the people were judged to be homosexual or heterosexual by their reports of sexual activity in the previous year. Both 35 percent of gay men and 35 percent of lesbians had one or more current psychiatric diagnoses, compared with 21 percent of heterosexual men and 22 percent of heterosexual women. Some 56 percent of gay me and 67 percent of lesbians had one or more lifetime psychiatric diagnoses, compared with 41 percent of heterosexual men and 39 percent of heterosexual women. These differences were statistically significant.

— Cited in Psychology for Living, Fall 2001, p. 22