The Pittsburgh Girls Study (PGS) has been funded by grants from the National Institute of Mental Health (MH056630, MH 48890), the Offi ce of Juvenile Justice and Delinquency Prevention (2013-JF-FX-0058), the National Institute on Drug Abuse (DA411018), and the Offi ce of Juvenile Justice and Delinquency Prevention (96-MU-FX-0012). Dr. Ahonen is grateful to the Swedish Research Council (Vetenskapsr?det) for supporting her research. We are much indebted to Magda Stouthamer-Loeber for her advice and for being the Co-Investigator responsible for starting and executing many of the initial waves of the Pittsburgh Girls Study. We are also indebted to Alison E. Hipwell, Stephanie Stepp, and Kate Keenan for carrying on the study, and to the study staff for their excellent work in collecting and preparing the data for analyses. Special thanks are due to Barbara Tatem- Kelley for her advice and assistance in many matters of grants management. We are very grateful to the girls, their parents, and teachers for their participation in the study over many years. The Pittsburgh Youth Study (PYS) has received funding from the Offi ce of Juvenile Justice and Delinquency Prevention of the US Department of Justice (96- MU- FX-0012; OJJDP 2005-JK-FX-0001), the National Institute of Mental Health (P30 MH079920; R01 MH73941; R01 MH 50778; 1K01MH078039), the National Institute on Drug Abuse (R01 DA411018), the National Institute on Alcohol Abuse and Alcoholism (ARRA R01 AA 016798), the Pennsylvania Department of Health (SAP 4100043365), and the Pew Charitable Trusts. The current analyses were greatly facilitated by Amy Carper and Rebecca Stallings, with the latter checking all references. We are also very grateful for the Pittsburgh Youth Study boys, their parents, and their teachers who participated across the many waves of the study, and for Magda Stouthamer-Loeber’s crucial involvement in the study, and for Dustin Pardini’s essential work on the later stages of the study