Cases were participants in STAR*D. Individuals (ages 18–75) were enrolled from primary care or psychiatric outpatient clinics if they had a diagnosis of MDD (by clinician rating of DSM-IV criteria) and a current 17-item Hamilton Depression Rating score of ≥14 by independent raters7, 8 (although that score did not capture the severity of past depression). Of 1,953 participants who donated DNA, we selected the 1,500 who self-identified as “white” as they represented most of the sample and European-ancestry controls were available. Following quality control (QC) procedures (described below), 1,221 cases were available for analyses. All subjects signed informed consent for genetic studies. Work described here was approved by the institutional review board of the University of California, San Francisco.
