The Early Developmental Stages of Psychopathology Study (EDSP): a methodological update.

The objectives of the community-based Early Developmental Stages of Psychopathology (EDSP) Study are described along with a detailed account of the overall design, special design features, sample characteristics and instruments used. The EDSP employed a prospective-longitudinal design to study substance use and other mental disorders in a representative population sample of 3,021 subjects aged 14-24 years (birth cohorts 1970-1981) at 'baseline' - the outset of the study. Two follow-up investigations were conducted after the baseline investigation covering an overall period of 3-4 years. Special design features are the linkage with a family supplement (EDSP-FS) as well as neurobiological laboratory studies of high-risk subjects.