I Introduction: Longitudinal Research and Intervention.- 1 Problems with Traditional Strategies in Mental Health Research.- II Methodological Bases of Longitudinal Research: Design and Planning.- 2 Some Problems of Longitudinal Research in the Social Sciences.- 3 Epidemiological Considerations.- 4 Issues in Psychological Development.- III Methodological Bases of Longitudinal Research: Tools.- 5 Disease Registers.- 6 Genetics and Classification.- 7 Statistical Models for Longitudinal Studies.- 8 Biological Measurements in Longitudinal Research.- IV Examples of Longitudinal Research: Birth, School, and Clinical Cohorts.- 9 A Prospective Longitudinal Study of the Relationship between Obstetrical Factors and CNS Damage.- 10 Twelve-Year Follow-Up Status of Low Birthweight Infants.- 11 The Value of Birth Cohort Studies.- 12 Sequential Research with Special References to the Scandinavian Project Metropolitan.- 13 Some Methodology and Strategy Problems in Longitudinal Research.- 14 Psychiatric Epidemiological Studies in Iceland.- V Examples of Longitudinal Research: Populations at Risk.- 15 Children of Schizophrenic Mothers: The Danish High-Risk Study.- 16 The Mauritius Project.- VI Longitudinal Research: Implications and Recommendations.- 17 Longitudinal Research in the WHO European Region Program.- 18 The Contribution of Long-Term Research to Social Medicine.- 19 Some Recommendations for the Design and Conduct of Longitudinal Investigations.- References.- List of Contributors.