This 10-12-year prospective follow-up of hyperactives as young adults (ages 17-24 years) attempted to determine which initial factors or group of factors (at ages 6-12 years) can predict adult outcome. Results indicate that any particular adult outcome is not associated with a particular initial variable but with the additive interaction of personality characteristics, social as well as family parameters. However, certain initial predictor variables stand out as being more important. These include family parameters such as socioeconomic class and mental health of family members, personal characteristics such as IQ, aggressivity, emotional instability, and low frustration tolerance.