In general, the study found that compared to heterosexual youths, the youths who had sexual experiences with a partner of their own sex but did not report same-sex romantic attraction were more socially integrated into their peer group and consumed more alcohol. On the other hand, adolescents who reported same-sex romantic attraction were poorly integrated into their peer group. Although they reported having social support from friends, they felt lonely and used more drugs. For this group, gender differences in substance use were small or the opposite of what was expected. By distinguishing youths with feelings of same-sex attractions from those with same-sex behavior only, the study identified a group of youths in which a relatively large minority might have a risk for future substance abuse or social isolation. The study, which was conducted in 2002, involved a school-based sample of 5,500 Norwegian 16-19 year-olds (92 percent response rate) with good population representation. Based on questionnaire responses, 2,459 boys and 1,989 girls were classified as having only heterosexual experiences and heterosexual attraction. Another group was composed of 94 boys and 609 girls who reported at least 1 of the listed sexual experiences with a same-sex partner but who reported no same-sex romantic or sexual attraction; most of these boys and girls reported heterosexual romantic attraction. The third group consisted of 79 boys and 241 girls who reported same-sex romantic or sexual attraction or both. 5 tables, 1 figure, and 75 references