Out of 3606 respondents in a survey of randomly sampled full-time undergraduates attending the University of Michigan, 10% (or about 361) reported at least one lifetime use of Ecstasy, 7% (about 252) reported Ecstasy use in the past year, and 3% (about 108) reported having used Ecstasy in the past month. (The survey was sent to 7000 students; half received the survey in the mail, and half received the survey over the Internet.) 11% of men and 10% of women reported ever having used Ecstasy. 11% of Whites, 4% of African Americans, 7% of Asian American, and 10% of "other" ethnicity reported ever having used Ecstasy. Freshmen reported the lowest percentage of lifetime Ecstasy use (7%) and seniors the highest (13%), but the authors note that this reflects the fact that seniors were generally older, and thus had more time in which to use Ecstasy. Undergraduates living in residence halls had the lowest rates of lifetime Ecstasy use (6%) while those living in houses or apartments, those living in fraternities or sororities, and those in "other" living arrangements had relatively similar rates of lifetime use (13%, 13% and 14%, respectively). Only 8% of those with GPAs of 3.5 or higher had ever used Ecstasy, while 14% of those with GPAs below 2.5 reported any lifetime Ecstasy use. 25% of gay, lesbian or bisexual respondents reported using Ecstasy at least once, compared with 10% of heterosexual respondents. 25% of undergraduates who had spent 10 or more hours attending parties reported lifetime Ecstasy use, while only 15% of those spending 5 to 9 hours, 9% of those spending 1 to 5 hours, and 3% of those reporting no more than 1 hour attending parties reported lifetime Ecstasy use. Lifetime Ecstasy use was significantly associated with all demographic variables listed except gender and parental education, and the relationship between lifetime Ecstasy use and GPA was on the cusp of significance. Logistical regressions were used to predict lifetime, yearly and monthly Ecstasy use, with demographic variables included as predictors. These models found that gender, ethnicity, and parental educational levels failed to predict yearly or monthly Ecstasy use. GPA predicted lifetime and yearly Ecstasy use, but not monthly use (with higher GPA associated with less likelihood of Ecstasy use). Sexual orientation and number of sexual partners predicted lifetime, yearly and monthly Ecstasy use. Pre-college Ecstasy use predicted yearly and monthly Ecstasy use, and number of hours spent attending parties predicted lifetime Ecstasy use, but no information is provided as to whether hours of party attendance predicted yearly and monthly Ecstasy use. Ecstasy using respondents were also more likely to use tobacco and cannabis, to drink alcohol, and to have binge drinking episodes in the previous two weeks. Study findings suggest that undergraduates reporting Ecstasy use are most likely to be White, gay, lesbian or bisexual, and to spend ten or more hours a week at parties. Similar findings from another college sample (Strote et al. 2002) also found Ecstasy-using undergraduates to be polydrug users who attended parties. A tendency toward novelty seeking and risk taking may be the common factor explaining why problem substance use (such as binge drinking) and higher number of sexual partners might be associated with Ecstasy use. The authors fail to offer an explanation for the association between Ecstasy use and sexual orientation.