Community-based study that prospectively traced the life course of a single-aged cohort from childhood to adulthood. Data were collected from multiple informants at seven major time points: age 5 (1977), age 6 (1978), age 9 (1980-1981), age 15 (1987), age 18 (1990), age 21 (1993-1994), and age 26 (1998). Traced the development and course of academic difficulties, behavior problems, and psychopathology; and identified factors that promoted health functioning from early childhood (age 5) to adulthood (age 26). The original study group was comprised of every child who entered kindergarten in the fall of 1977 in one public school district in a northeastern town in the United States. For Wave 7, respondents were 26 years old in 1998. In addition to diagnostic information, participants reported on their current employment, functioning, and family relationships.