This study was funded by National Institutes of Health grant P50MH090966 (Project 1, Dr. Brown and Dr. Sourander, co–principal investigators) and by the Sackler Center for Developmental Psychobiology at Columbia University. Dr. Gyllenberg was funded by the Sigrid Juselius Foundation, by the Finnish Medical Association, and by the Foundation for Pediatric Research in Finland.
The authors report no competing interests.