1. T. Porkka-Heiskanen, Department of Psychiatry, Harvard Medical School, Brockton Veterans Administration Medical Center (VAMC), 116 A, 940 Belmont Street, Brockton, MA 02401, USA, and Institute of Biomedicine, University of Helsinki, Helsinki, Finland.
2. R. E. Strecker, M. Thakkar, A. A. Bjørkum, R. W. Greene, R. W. McCarley, Department of Psychiatry, Harvard Medical School, Brockton VAMC, 116 A, 940 Belmont Street, Brockton, MA 02401, USA.