For this study, we restricted analyses to participants to who responded to the 2011 questionnaire, when family his functioning and quality of parental-adolescent relationship were assessed (n=6659). Participants missing data on family functioning and quality of parental-adolescent relationship were excluded from the analyses (n=277), resulting in an analytic sample of 6382(3768 females and 2614 males). In the analytic sample, 21% had at least one sibling in the cohort(5013 unique families) The study was approved by the Partners Human Research Committee.