Of the 11 studies from the PGC-SUD workgroup, seven were case-control studies and four were family-based studies (Supplementary Table 1; Supplementary Methods). Lifetime OD diagnoses was based on DSM-IV OD criteria15 and were derived either from clinician ratings or semi-structured interviews. The two control groups included OE controls (individuals without a lifetime OD diagnosis who were exposed to opioids at least once) and OU controls (individuals with no lifetime OD diagnosis who were not exposed to opioids). Lifetime opioid exposure included both licit, prescribed opioids and those used outside appropriate medical care. Some, but not all, studies distinguished between these forms of exposure. This study, which involved the analysis of de-identified data, was approved by the institutional review board (IRB) at Yale University School of Medicine and was conducted in accordance with all relevant ethical regulations. Each contributing study obtained informed consent from participants and ethics approvals for their study protocols from their respective review boards in accordance with applicable regulations.
