Discriminating primary clinical states in bipolar disorder with a comprehensive symptom scale Introduction Systematically obtained data on the spectrum of symptomatology in various mood states of bipolar disorder (BD) are limited. Reviews indicate widely varying rates of individual symptoms in syndromal states within BD (1). The criteria in DSM-IV TR constrain comprehensive assessments of BD symp- Singh V, Bowden CL, Gonzalez JM, Thompson P, Prihoda TJ, Katz MM, Bernardo CG. Discriminating primary clinical states in bipolar disorder with a comprehensive symptom scale. Objective: We assessed the spectrum and severity of bipolar symptoms that differentiated bipolar disorder (BD) clinical states, employing the Bipolar Inventory of Symptoms Scale (BISS) which provides a broader item range of traditional depression and mania rating scales. We addressed symptoms differentiating mixed states from depression or mania ⁄ hypomania. Method: One hundred and sixteen subjects who met DSM-IV-TR criteria for BD and were currently in a depressed, manic ⁄ hypomanic, mixed episode, or recovered state were interviewed using the BISS. Results: A subset of manic items differed between mixed episodes and mania ⁄ hypomania or depression. Most anxiety items were more severe in mixed subjects. BISS Depression and Manic subscales differentiated episodes from recovered status. The majority of depression and manic symptoms differentiated mood states in the predicted direction. Mixed episodes had overall greater mood severity than manic ⁄ hypomanic episodes or depressed episodes. Conclusion: These results indicate that a small subset of symptoms, several of which are absent in DSM-IV-TR criteria and traditional rating scales for bipolar studies, aid in distinguishing mixed episodes from depressive or manic ⁄ hypomanic episodes. The results also support the utility of a comprehensive BD symptom scale in distinguishing primary clinical states of BD. V. Singh, C. L. Bowden, J. M. Gonzalez, P. Thompson, T. J. Prihoda, M. M. Katz, C. G. Bernardo Department of Psychiatry, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA Key words: bipolar disorder; rating scales; clinical status; psychometrics; mixed episodes Jodi M Gonzalez, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, Texas 78229, USA. E-mail: gonzalezjm1@uthsca.edu Accepted for publication May 22, 2012 Significant outcomes • Anxiety symptoms are particularly severe in mixed episodes. • Mixed episodes of bipolar disorder carry the greatest total illness severity. • DSM-IV-TR symptom profiles do not adequately depict the most common presentation of bipolar mood episodes, particularly mixed episodes. Limitations • These data were collected on an out-patient sample, and in-patient symptom severity may differ. • Medications may have impacted symptom presentation. • This is a cross-sectional study. Acta Psychiatr Scand 2013: 127: 145–152 All rights reserved DOI: 10.1111/j.1600-0447.2012.01894.x Ó 2012 John Wiley & Sons A/S ACTA PSYCHIATRICA SCANDINAVICA 145