Features of mood associated with high body weight in females with fibromyalgia

BACKGROUND: Fibromyalgia (FM) is a common syndrome whose main characteristic is chronic widespread musculoskeletal pain, the severity of which is frequently worsened by concomitant obesity. Major depression (MD), particularly as part of a bipolar spectrum disorder (BSD), is associated with both obesity and FM. OBJECTIVE: To evaluate the relationship between lifetime MD, hypomanic symptoms and the body mass index (BMI) in patients with FM. METHOD: Of the 115 patients originally screened, 87 women with FM finally entered the study. Forty-nine patients (57%) had a lifetime diagnosis of MD, assessed by a structured clinical interview based on DSM-IV criteria, and four of them (4.6%) had a current MD episode. Lifetime hypomanic symptoms were measured by means of the self-rated Hypomania Checklist. According to the international criteria for BMI, FM patients were classified as under/normal-weight (61%), overweight (30%) and obese (9%). RESULTS: 62 patients (71.2%) with FM had a bipolar spectrum disorder (BSD). Thirty (48.3%) of them met criteria for bipolar II disorder, 32 (51,6%) for bipolar disorder NOS (18 FM patients with MD associated to sub-syndromal hypomanic syndrome and 14 with hypomanic syndrome without MD). No patient had a bipolar I disorder. Only one patient met the criteria for a major depressive disorder (MDD). There was no significant difference in mean BMI between the patients with and without a lifetime diagnosis of MD, but there was a positive association between the level of hypomanic symptoms and BMI values (p<0.009). When hypomania was considered categorically as hypomanic syndrome there was no significant effect on BMI. CONCLUSIONS: Our finding adds to previous evidence indicating that hypomanic symptoms are a central feature of FM. In the case of the early identification of high-level hypomanic symptoms, body weight should be closely monitored in order to prevent obesity and its detrimental impact on females with FM.