Control subjects were selected from those ascertained through a NIMH-supported contract mechanism between Dr. Pablo Gejman and Knowledge Networks, Inc. All subjects donated a blood sample and were given a medical questionnaire. The selected controls were matched for gender and ethnicity with the BD cases, and all subjects who endorsed a history of BD, psychosis, or major depression were excluded. A total of 1,434 controls of European Ancestry were available for analysis.
