Research reportPsychotic versus non-psychotic bipolar II disorder
Introduction
In 1994 the DSM-IV (American Psychiatric Association, 1994) officially included bipolar II disorder as a specific nosologic category. According to this nosographic system, diagnosis of bipolar II disorder hinges on the presence or history of one or more major depressive episode and the presence or history of at least one hypomanic episode. In recent years, through an increasing number of data, bipolar II disorder has been recognized as a distinct category within mood disorders (Vieta and Suppes 2008). Reported differences between bipolar II and the other two adjacent categories, bipolar I and major depressive disorder (MDD, also called unipolar depression), include genetic, biological, clinical, and therapeutic aspects ( Yatham, 2005, Berk and Dodd, 2005, Vieta and Suppes, 2008).
Most of the available data on bipolar II disorder come from studies that compare populations of patients with bipolar II disorder with bipolar I patients and/or MDD patients. Only a few studies have been conducted on samples composed exclusively of bipolar II patients. The aim of these studies was to test if there were distinct clinical subtypes according to age at onset (Benazzi, 2000a), presence or absence of comorbidity (Vieta et al., 2000) as well as of melancholic features (Benazzi, 2000b) and gender differences (Benazzi, 2006).
Psychosis occurs frequently during mood episodes in patients with bipolar disorder (Goodwin and Jamison, 2007) and in patients with bipolar mania, rates of psychotic symptoms up to 68% have been reported (Keck et al., 2003). The DSM-IV assumes the presence of psychotic symptoms as a marker of severity of the bipolar disorder but not as a diagnostic criteria, reinforcing the arguable idea that psychosis is a core feature of schizophrenia but not of bipolar disorder (Vieta and Phillips, 2007). Moreover, its role as course specifier is still controversial (Colom and Vieta, 2009). Although some studies report psychotic symptoms associated with longer hospitalizations (Kessing, 2004), more time ill (Geller et al., 2004), overall impairment (Haro et al., 2006), increased recurrence (Tohen et al., 2003), greater symptom severity and higher morbidity in the long-term (Coryell et al., 2001), other studies point at a lack of prognostic relevance (Keck et al., 2003, Goldberg and Harrow, 2004).
Research on the presence and prognostic value of psychotic features performed with samples composed exclusively by bipolar II patients is scanty and offers some contradictory results. Lifetime history of psychotic symptoms in bipolar II, which can occur by definition only during a depressive episode, is present in a range between 3% and 45% (Vieta et al., 1997, Yildiz and Sachs, 2003, Mantere et al., 2004, Goes et al., 2007, Brugue et al., 2008). This huge variation between studies may be related to several demographic and methodological issues i.e., sample selection biases. To the best of our knowledge, there is no published research that focuses specifically on the impact of lifetime history of psychotic symptoms on the clinical course of bipolar II patients by comparing bipolar II patients with and without a history of psychosis.
Section snippets
Method
The sample of the present study consisted of 164 consecutive patients with a diagnostic of bipolar affective disorder type two—according to DSM-IV-TR criteria—elicited by two independent psychiatrists, treated and followed up at the Hospital Clinic de Barcelona (Catalonia, Spain) whose Ethics and Research Committees approved the study.
All patients included in the present study were enrolled in the systematic prospective follow up of the Bipolar Disorders Program of the Hospital Clinic and
Results
Thirty-two of 164 patients with bipolar II disorder (19.5%) had a lifetime history of psychotic symptoms. Comparisons among bipolar II patients with and without psychotic history are presented in Table 1 (continuous variables) and in Table 2 (categorical variables). Psychotic patients were older and had significantly more hospitalizations (P < 0.001). Although the total number of affective episodes was higher for the non-psychotic, differences did not reach the level for statistical significance.
Discussion
The rate of bipolar II patients with a lifetime history of psychotic symptoms found in this study (19.5%) was within the range reported in literature (Yildiz and Sachs, 2003, Mantere et al., 2004, Goes et al., 2007). A previous report from our Program, which compared non consecutive bipolar I and II patients, found a prevalence of psychosis of 12.5% in bipolar II (Brugue et al., 2008), which is lower, but the sample was less representative than the present one. A high number of hospitalizations
Role of funding source
The authors of this study would like to thank the support of the Spanish Ministry of Science and Innovation, Instituto de Salud Carlos III (PI080180 and PI08/90094), CIBERSAM and the Generalitat de Catalunya to the Bipolar Disorders Group (2009 SGR 1022). Francesc Colom, PhD, is funded by the Spanish Ministry of Science and Innovation, Instituto Carlos III, Madrid, Spain, through a ‘‘Miguel Servet’’ postdoctoral contract (CP08/00140) and a FIS (PS09/01044). Nuria Cruz, MD is funded by the
Conflict of interest
Lorenzo Mazzarini, Alessandra MA, Nivoli, Andrea Murru, C Mar Bonnin, Nuria Cruz, José Sánchez-Moreno and Giorgio D. Kotzalidis have no conflict of interests.
Francesc Colom has served as advisor or speaker for the following companies: Astra Zeneca, Bristol-Myers, Pfizer Inc, Glaxo-Smith-Kline, Eli Lilly, Sanofi-Aventis, Otsuka, Tecnifar & Shire.
Paolo Girardi has received in the past research support from Lilly and Janssen and honoraria from Lilly and Organon, and has also participated in
Acknowledgements
The authors of this report would like to thank the support of the Spanish Ministry of Science and Innovation, Instituto de Salud Carlos III, CIBERSAM, the Spanish Ministry of Education and the Generalitat de Catalunya.
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