Statistics suggest that the incidence of depression and suicide increase over the course of adolescence. Other research suggests that many indicators of well-being increase over the course of adolescence as well. This study investigated affective development during adolescence and examined the relationship of gender, normative developmental changes in early adolescence, and parental relationships to affective development patterns. Subjects were 254 sixth graders who participated in a longitudinal study through eighth grade. A subsample of students were involved in a follow-up study in their senior year of high school. Depressive affect was measured in several ways throughout the years of the research. The results revealed that, in early adolescence, there were usually no significant sex differences in self-image or depression. By grade 12 however, boys reported more positive feelings than did girls. High associations were found among several measures of depression and well-being in the last year of high school. Girls were much more likely than boys to report depressed mood by grade 12, suggesting that gender becomes a more potent organizer of depressed mood over adolescence. Regardless of gender, subjects who were distressed throughout early adolescence were much more likely to report poorer self-images by grade 12. This finding suggests that poor mood in early adolescence is not transient but rather quite predictive of later depressive mood. (NB)