[1] Univ Penn, Perelman Sch Med, Dept Psychiat, Philadelphia, PA 19104 USA
[2] Univ Penn, Perelman Sch Med, Dept Radiol, Philadelphia, PA 19104 USA
[3] Univ Penn, Perelman Sch Med, Dept Neurol, Philadelphia, PA 19104 USA
[4] Univ Penn, Perelman Sch Med, Dept Biostat Epidemiol & Informat, Philadelphia, PA 19104 USA
[5] Philadelphia Vet Adm, Med Ctr, Philadelphia, PA USA