Brief report Impact of anxiety disorder comorbidity on quality of life in euthymic bipolar disorder patients: differences between bipolar I and II subtypes Umberto Albert, Gianluca Rosso, Giuseppe Maina ⁎ , Filippo Bogetto Department of Neurosciences, Mood and Anxiety Disorders Unit, University of Turin, Italy, Via Cherasco 11 - 10126 Torino, Italy Received 20 April 2007; received in revised form 24 May 2007; accepted 24 May 2007 Available online 6 July 2007 Abstract Background: Few studies investigated the impact of anxiety disorder comorbidity on health-related quality of life (HRQoL) of bipolar patients and none examined bipolar subtypes differences. The aim of the study was 1) to determine comorbidity rates for anxiety disorders in euthymic bipolar subjects, comparing bipolar type I and II disorders (BDI and BDII), and 2) to compare within each group HRQoL measures in subjects with and without anxiety comorbidity. Methods: Comorbidity was evaluated through the SCID-I; HRQoL was assessed using the 36-Item Short-Form Health Survey (SF-36). All subjects were euthymic since at least 2 months, as confirmed by a HAM-D b 8 and a YMRS b 6. A comparison was made for SF-36 scores between subjects (all bipolars, BDI and BDII) with and without anxiety disorders. Results: 105 patients were enrolled: 44 with BDI and 61 with BDII. Current and lifetime anxiety disorders comorbidities were 32.4% and 41.0% for all bipolars, 31.8% and 40.9% for BDI and 32.8% and 41.0% for BDII. BDI patients differed in several SF-36 domains from BDII subjects, which reported a poorer HRQoL. A current and lifetime comorbid anxiety disorder was associated with a poorer HRQoL considering all bipolars; when examining separately BDI and II subjects, however, the deleterious effect was restricted to BDI patients. Limitations: The cross-sectional assessment of HRQoL, the generic instrument used (SF-36) and the small sample size. Conclusions: Our study confirms the high comorbidity rates for anxiety disorders in bipolar subjects and provides evidence that anxiety comorbidity impacts HRQoL in subjects with BDI and not BDII. © 2007 Elsevier B.V. All rights reserved. Keywords: Bipolar disorder; Anxiety disorder; Health-related quality of life; Comorbidity 1. Introduction Health-related quality of life (HRQoL) of bipolar disorder subjects is impaired even during euthymia (Namjoshi and Buesching, 2001; Dean et al., 2004; Michalak et al., 2005). Preliminary evidence, moreover, suggests that differences exist between bipolar disorder type I (BDI) and II (BDII), with a greater impairment in BDII (Maina et al., 2007). A detrimental effect of anxiety disorder (AD) comorbidity has been reported on HRQoL of bipolar subjects; given the high current and lifetime comorbidity rates between anxiety and bipolar disorders (Keller, 2006; McIntyre et al., 2006), however, it is surprising that only two studies examined this issue (Simon et al., 2004; Bauer et al., 2005). The first study (Simon et al., 2004) reported that a current AD comorbidity was associated with Journal of Affective Disorders 105 (2008) 297 – 303 www.elsevier.com/locate/jad ⁎ Corresponding author. Tel.: +39 11 6335425; fax: +39 11 673473. E-mail address: giuseppemaina@hotmail.com (G. Maina). 0165-0327/$ - see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.jad.2007.05.020