Research report Mania and depression. Mixed, not stirred Isabella Pacchiarotti a,b , Lorenzo Mazzarini a,b,c , Giorgio D. Kotzalidis a,b , Marc Valentí a , Alessandra M.A. Nivoli a , Gabriele Sani b , Carla Torrent a , Andrea Murru a , Jose Sanchez-Moreno a , Barbara Patrizi a,b , Paolo Girardi b,c , Eduard Vieta a, ⁎, Francesc Colom a a Bipolar Disorders Program, Institute of Neurosciences, Hospital Clinic Barcelona, IDIBAPS, CIBERSAM, University of Barcelona, Barcelona, Catalonia, Spain b Unit of Psychiatry, Department of Neurosciences, Sant'Andrea Hospital, 2nd Medical School, Sapienza University, Rome, Italy c Department of Neuropsychiatry, Villa Rosa, Suore Hospitaliere of the Sacred Heart of Jesus, Viterbo, Italy article info abstract Article history: Received 11 January 2011 Received in revised form 23 March 2011 Accepted 23 March 2011 Available online 22 April 2011 Objective: Current criteria for mixed bipolar episode do not allow an adequate understanding of a vast majority of bipolar patients with mixed (hypo) manic-depressive features, keeping the qualification of “mixed episodes” for bipolar type I only. This study was aimed to test the existence of a bipolar-mixed continuum by comparing the characteristics of three groups classified according to patterns of past and current manic or mixed episodes. Method: 134 bipolar I inpatients were divided according to their pattern of excitatory “mixed- like” episodes in three groups: 1) lifetime history of purely manic episodes without mixed features (PMA); 2) lifetime history of both manic and mixed episodes (MIX) and 3) lifetime history exclusively of mixed, but not manic, episodes (PMIX). Differences in clinical and demographic characteristics were analyzed by using chi-square head-to-head for categorical data, one-way ANOVA for continuous variables and Tukey's post-hoc comparison. Logistic regression was used to control for data validity. Results: PMIX had higher rates of depressive predominant polarity and less lifetime history of psychotic symptoms, and had received more antidepressants both lifetime and during 6 months prior to index episode. PMIX had more suicide attempts and Axis I comorbidity than PMA. Discussion: PMIX is likely to have a higher risk for suicide and higher rates of comorbidities; current DSM-IV-TR criteria are not fit for correctly classifying these patients and this may affect treatment appropriateness. The concept of “mixicity” should be extended beyond bipolar I disorder to other bipolar disorder subtypes. © 2011 Elsevier B.V. All rights reserved. Keywords: Bipolar disorder Type I Clinical course predictors Suicide Predominant polarity Mixed episode 1. Introduction Mixed states are broadly defined as the coexistence of both manic and depressive features within the same mood episode. Mixed states were first described by Emil Kraepelin (1899) and Wilhelm Weygandt (1899). These authors pointed at these episodes as the cornerstone of manic-depressive insanity. Since then, the definition of mixed states by the nosology has suffered from several changes: in the first edition of the DSM (American Psychiatric Association, 2000), for instance, the term “manic depressive reaction, mixed type” was used rather loosely, while the second edition (1968) required that “manic and depressive symptoms appeared almost simultaneously” in order to diagnose “mixed” manic-depressive. In the DSM-III (1980) and DSM-III-R (1987), the diagnosis of bipolar disorder, mixed, required the “full symptomatic picture of both manic and major depressive episodes, intermixed or rapidly alternating every few days”, whereas in the DSM-IV (1994) and the DSM-IV-TR Journal of Affective Disorders 133 (2011) 105–113 ⁎ Corresponding author at: Clinical Institute of Neuroscience, University Clinic Hospital of Barcelona, Villarroel 170, 08036-Barcelona, Spain. Tel.: + 34 93 2275401; fax: +34 93 2275795. E-mail address: evieta@clinic.ub.es (E. Vieta). 0165-0327/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.jad.2011.03.037 Contents lists available at ScienceDirect Journal of Affective Disorders journal homepage: www.elsevier.com/locate/jad