RESEARCH ARTICLE Chronic multisite pain in m c k

DOI 10.1186/s12888-014-0350-4studies investigating the association between chronic painUK Full list of author information is available at the end of the articleBackground Chronic pain is known to be associated with depressive features and major depressive disorder (MDD) [1,2] but the association between chronic pain and bipolar disorder (BD) has received less attention. Very few studies have in-vestigated associations between chronic multisite pain (pain occurring at two or more body sites [3]) and mood disorders, although there is some evidence of a positive correlation between number of chronic pain sites and de-pressive features [4]. A study of the health records of 5 million US Veterans Affairs patients found that those with MDD or BD were 1.8 and 2.6 times more likely, respectively, to have a diagnosis of one or more painful conditions in their health records than non-mood disordered controls [5]. The prevalence of chronic pain was reported to be 23.7 % in a meta-analysis of chronic pain in BD studies; and patients with BD were found to be at a two-fold increased risk of having chronic pain compared to the general population [6]. Two furthe