The second data collection wave, which began in 1996 and continued through 2005, targeted Wave 1 probands, members of densely affected families, and comparison family members. 12 In addition, other family members in the Wave 1 families who had not been assessed in the previous wave were assessed in Wave 2. Also in Wave 2, a seventh data collection site, located at Howard University in Washington DC, was added to increase the racial/ethnic diversity of the sample, with an emphasis on Black families. The SSAGA was updated to reflect the change in diagnostic classification system from DSM‐3R to DSM‐IV, 13 adding new items but retaining the old to preserve consistency across assessment waves. The key elements of the protocol in Wave 2, including the interview, questionnaires, and electrophysiological assessments, remained largely unchanged. Additional neuropsychological tests were included to evaluate participants' decision‐making, memory, attention, and problem solving, and, if not previously collected, a blood sample was taken for genetic analyses and cell lines. Children aged 7–17 were also re‐interviewed, and additional children in the families were recruited. Altogether, 8799 adults aged
