assessment are reported elsewhere11,15. After excluding participants with missing stimulant use or basic demographic information, the remaining sample consisted of 614 small nuclear families (1355 total participants) and 10,084 unrelated individuals. An independent sample consisting of 532 EA cases, 7635 EA controls, 53 AA cases, and AA 3352 controls was selected from the Collaborative Study on the Genetics of Alcoholism (COGA)16 for replication. Diagnoses in the COGA sample were made using the SSAGA, a semi-structured interview from which the SSADDA was derived17. Characteristics of stimulant-dependent cases and controls in the discovery and replication datasets are shown in Table 1. This study was approved by the Institutional Review Boards at all participating sites. Data were analyzed between September 2017 and October 2019.Table 1Sample characteristics.StageDatasetGroupAfrican AmericansEuropean AncestryFemale/totalAge µ (SD)Female/totalAge µ (SD)DiscoveryYale-Penn1Case32/10147.0 (7.8)73/16940.5 (10.0)Control1427/298640.8 (9.0)603/139437.7 (11.0)Yale-Penn2Case10/3848.1 (10.9)48/13642.0 (13.2)Control684/161740.6 (11.0)615/146139.1 (13.0)Yale-Penn3Case6/1649.8 (11.0)20/8841.4 (11.4)Control486/100040.5 (11.4)1,219/242340.5 (14.6)ReplicationCOGACase21/5340.6 (8.5)222/53236.8 (9.3)Control1783/329932.7 (12.2)3798/710336.8 (15.2)
