P ostoperative but not preoperative depression is associated with cognitive impairment after cardiac surgery: exploratory analysis of data from a randomized trial oleh Choy Lewis, Mehmet E. Dokucu, Charles H. Brown, Lauren Balmert, Nina Srdanovic, Ashwin Shaan Madhan, Sahej Singh Samra, John Csernansky, Jordan Grafman, Charles W. Hogue