Despite the assumption that marriage enhances psychological well-being, little evidence exists that the social role of marriage, rather than the characteristics of individuals who get married, accounts for the benefits of marriage. We use a sample of 18-, 21-, and 24-year-old men and women who either remained unmarried or got and remained over a 7-year period to examine whether, after controlling for premarital rates of disorder, marriage enhances mental health. In addition, we consider whether or not females derive more mental health benefits from marriage than males. The results indicate that, with controls for premarital rates of mental health, young adults who get and stay do have higher levels of well-being than those who remain single. In addition, although men-but not women-who become report less depression, women-but not men-who become report fewer alcohol problems. Thus, when both male-prevalent and female-prevalent outcome measures are used, both men and women benefit from marriage. Key Words: marriage, mental health, social selection, young adults. For the past century, sociologists have assumed that marriage enhances psychological well-being. A hundred years ago, Durkheim (1897/1951) postulated that the low suicide rates of people were due to their greater social integration, protection from life strains, and sense of security, meaningfulness, and purpose. Many studies since that time show that marriage is associated with less morbidity, mortality, mental illness, substance abuse, and distress (e.g., Adler, 1953; Bloom, Asher, & White, 1978; Gove, 1972; Ross, Mirowsky, & Goldstein, 1990; Ross, 1995; Umberson, 1987; Waite, 1995). Indeed, one survey of the literature states that no social variable is more consistently or more powerfully related with the distribution of psychopathology than marital status (Bloom et al., 1978). Another survey concludes that one of four major social patterns of distress is that married people are less distressed than unmarried ones (Mirowsky & Ross, 1989, p. 90). Despite the widespread consensus regarding the benefits of marriage, a number of questions persist about the relationship between marital status and mental health. Although people have better mental health than unmarried people, little evidence indicates that the social role of being married, rather than the characteristics of individuals who get married, is responsible for this advantage. The relationship between marital status and well-being might exist because healthier people get married, not because marriage makes people healthier. People with better psychological well-being may be more likely to get in the first place and to remain married. Conversely, poor mental health might be a hindrance to marriage and a precursor of marital dissolution. Without controls for preexisting psychological states, the possibility that people with better psychological health are selected into marriage and the most distressed remain unmarried cannot be ruled out (Mastekaasa, 1992). Yet, most studies of marriage and mental health are crosssectional so they cannot test the possibility of selection effects into varying marital statuses. Not only possible selection effects, but also the failure to separate different unmarried statuses create difficulties in interpreting how marriage affects well-being. Some studies combine different unmarried statuses, such as separated, divorced, and widowed people, with never-married people in comparisons with the (e.g. Pearlin & Johnson, 1977; Thoits, 1987). Yet the advantage of the is clearest when compared with separated or divorced people (e.g., Gerstel & Reissman, 1984; Umberson, 1987; Williams, Takeuchi, & Adair, 1992). In contrast, little empirical support exists for the mental health advantages of marriage compared with never marrying, with the exception of psychotic disorders (Eaton, 1980). …