Eur Arch Psychiatry Clin Neurosci (2011) 261:341–347 DOI 10.1007/s00406-010-0187-x O R I G I N A L P A P E R Decreasing the minimum length criterion for an episode of hypomania: evaluation using self-reported data from patients with bipolar disorder Michael Bauer • Tasha Glenn • Natalie Rasgon • Wendy Marsh • Kemal Sagduyu • Paul Grof • Martin Alda • Greg Murray • Rodrigo Munoz • Danilo Quiroz • Rita Bauer • Burkhard Jabs • Peter C. Whybrow Received: 23 July 2010 / Accepted: 23 December 2010 / Published online: 26 January 2011 The Author(s) 2011. This article is published with open access at Springerlink.com Abstract Brief hypomania lasting less than 4 days may impair functioning and help to detect bipolarity. This study analyzed brief hypomania that occurred in patients with bipolar disorder who were diagnosed according to the DSM-IV criteria. Daily self-reported mood ratings were obtained from 393 patients (247 bipolar I and 146 bipolar II) for 6 months (75,284 days of data, mean 191.6 days). Episodes of hypomania were calculated using a 4, 3, 2, and single day length criterion. Brief hypomania occurred fre- quently. With a decrease in the minimum criterion from 4 days to 2 days, there were almost twice as many patients with an episode of hypomania (102 vs. 190), and more than twice as many episodes (305 vs. 863). Single days of hypomania were experienced by 271 (69%) of the sample. M. Bauer (&) B. Jabs Department of Psychiatry and Psychotherapy, Universita¨tsklinikum Carl Gustav Carus, Technische Universita¨t Dresden, Germany Fetscherstr. 74, 01307 Dresden, Germany e-mail: michael.bauer@uniklinikum-dresden.de T. Glenn ChronoRecord Association, Inc., PO Box 3501, Fullerton, CA 92834, USA URL: http://www.chronorecord.org N. Rasgon Department of Psychiatry and Behavioral Sciences, Stanford School of Medicine, Palo Alto, CA, USA W. Marsh Department of Psychiatry, University of Massachusetts, 55 Lake Avenue North, Worcester, MA 01655, USA K. Sagduyu Department of Psychiatry, University of Missouri Kansas City School of Medicine, Kansas City, MO, USA K. Sagduyu PO Box 23430, Stanley, KS 66283, USA P. Grof Mood Disorders Center of Ottawa, 1929 Russell Road, K1G 4G3 Ottawa, Canada P. Grof Department of Psychiatry, University of Toronto, Toronto, ON, Canada M. Alda Department of Psychiatry, Dalhousie University, 5909 Veteran’s Memorial Lane, QEII Health Sciences Centre, Halifax, NS B3H 2E2, Canada G. Murray Faculty of Life and Social Sciences, Swinburne University of Technology, PO Box 218, John St., Hawthorn 3122 Melbourne, Victoria, Australia R. Munoz Department of Psychiatry, University of California San Diego, San Diego, CA, USA D. Quiroz Mood Disorder Clinic EFESO, Apoquindo 4100 Suite 701, Santiago 7550112, Chile R. Bauer Department of Psychiatry and Psychotherapy, University of Regensburg, Universita¨tsstrasse 84, Regensburg 93053, Germany P. C. Whybrow Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior University of California Los Angeles (UCLA), 300 UCLA Medical Plaza, Los Angeles, CA 90095, USA 123