The original interviews of mothers covered a broad range of child health, development, temperament, and problems as well as structural and functional information on the family. Three coordinated forms of the interview covered the child ages of one year, 2-4 years, and 5-10 years, with the same overall content obtained by inquiries about age-appropriate behaviors. The basic information in the interview for children ages 5 to 10 was sought at each of the follow-up interviews of mothers, with parallel questions also asked of youth regarding their own behavior. To this mother interview was added a section on her own personality and attitudes, additional scales on child rearing and parent-child relationship, an interview regarding the psychiatric symptoms of the child (Diagnostic Interview Schedule for Children, [DISC], Costello et al, 1984), and service usage, as well as a measure of children's values. The child interview began with information about the neighborhood and school environment, and included personality and attitude measures, parallel measures on parenting and parent-child relationship, peer relationship, health, the child version of the DISC, and a vocabulary measure of verbal intelligence. Information was pooled from the mother and youth interviews to cover the criteria for DSM Axis II personality disorders. The youth interviews were essentially the same at T2, T3, and T4, except that a number of items were added in the third and fourth waves that covered aspects of the residential and social settings of adolescents and young adults, as well as additional data relevant to diagnostic criteria, and life goals. At T4 mothers provided data on history of somatic and psychiatric disturbances for all family members. At T5 only youth were interviewed, using an interview that included parts of the Combined International Diagnostic Interview. The sibling sample was interviewed with the same protocol as the second follow-up; mothers were again interviewed with regard to the second child.The Offspring study
Beginning in the late 1980's, as youth in the sample began to have babies, studies of this second generation were begun, sponsored by the National Institute of Mental Health and the National Institute on Drug Abuse. In these studies mother and father interviews and questionnaires, infant observation and assessments, including videotapes, and certain bioassays were collected on about 100 infants at age 12 months, and, in ongoing data collection, on over 200 infants at age 24 months, with a mailed-in assessment at infant age 18 months. A NIDA sponsored study continues to follow offspring when they reach school-age.