Strengths of this study are a relatively large sample size, including SAGE data to increase power. All subjects were assessed using comprehensive, standardized instruments. Our primary sample has unusually good representation of AA subjects. Most of the strongest findings emerged from this understudied population; some of these were supported by findings from the EAs. We employed several novel analytic strategies, including models defining OD symptoms as a quantitative trait adjusted for addiction to other substances. Such approaches minimize concern about the misclassification of controls because SD requires exposure to the drug. An overall picture emerges of genes and pathways involved in regulating calcium and potassium signaling as major contributors to OD risk.
