Fibromyalgia syndrome and depressive symptoms: Comorbidity and clinical correlates

Abstract

Objective

Fibromyalgia is characterized by chronic widespread musculoskeletal pain and higher pain perception in specific anatomic sites called tender points. Fibromyalgia is frequently associated with psychiatric symptoms, like depression and anxiety; indeed some authors have argued about the possibility to classify this syndrome into affective spectrum disorder. Few studies have analyzed the impact of depressive symptoms on pain threshold. This research is aimed at evaluating the prevalence and the clinical correlates of depressive symptoms in fibromyalgic patients, and investigating their impact on pain perception and quality of life.

Methods

Outpatients between 18 and 75 years with diagnosis of fibromyalgia according to the criteria of the American College of Rheumatology have been included. All subjects have been evaluated with the following rating scales: HAM-D; VAS (to quantify pain); a visual analogical scale to evaluate quality of life; and Paykel's List of Recent Life Events.

Results

Thirty subjects have been recruited. Most patients (83.3%) had clinically significant depressive symptoms as indicated by a HAM-D score > 7. Depressive symptoms are associated with higher pain perception, worse quality of life and more severe life events.

Conclusion

The presence of depressive symptoms is associated with a great impairment in patients with fibromyalgia syndrome: indeed the psychiatric comorbidity lowers pain threshold and worsens the quality of life of our patients. Future studies should be conducted in order to identify the individual factors, e.g. stress or inflammatory processes, which drive the association between depression and higher severity of fibromyalgia syndrome.

Introduction

Fibromyalgia is a common syndrome of unknown etiology classified among extra-articular rheumatisms of functional nature, characterized by chronic widespread musculoskeletal pain, heightened and painful response to tactile stimuli, and the presence of eleven or more “tender points” in specific anatomic sites (18 specific points at 9 bilateral sites) that are exceptionally sensitive to the touch (Chakrabarty and Zoorob, 2007) (Table 1).

FM is frequent in population and clinical samples: the prevalence was estimated between 0.5% and 5% in general population studies and up to 15% in clinical samples across different countries (White and Harth, 2001, Neumann and Buskila, 2003).

In Italy the reported lifetime prevalence is 2.2% Branco et al., 2010). Fibromyalgia is more common in women than in men, affecting the 3.4% of women versus the 0.5% of men (Wolfe et al., 1990).

In fibromyalgia the pain is often associated with a heterogeneous profile of autonomic and neuropsychiatric symptoms. For example, a recent study has found that the majority of patients had nausea, constipation, colicky abdominal pain, orthostatic hypotension, and dizziness (Solano et al., 2009). Besides, psychiatric symptoms such as depressive, anxious and sleep disorders have frequently been associated to FM (Berger et al., 2007, Raphael et al., 2006).

The physical and mental distress experienced by FM patients strongly affects quality of life, social and work performances, to the point that FM has been called the “invisible disability” (Sturge-Jacobs, 2002). Subjects suffering from fibromyalgia show more functional disability, less ability to adapt to limitations imposed by the disease and more tendency to emphasize the pain, compared with patients with rheumatoid arthritis (Walker et al., 1997).

Furthermore, patients with FM are frequently diagnosed with depressive and anxiety disorders (Bradley, 2005, Wolfe et al., 1990). A recent review has reported that depressive disorders are the most frequent psychiatric comorbidity in patients with FM, with prevalence rates ranging from 20% to 80% (Fietta et al., 2007). Depressive symptoms are also frequent in patients with FM, with prevalence rates around 40% (Kato et al., 2006).

Although there are several studies investigating the extant comorbidity between depressive disorders and symptoms and FM, data regarding the impact of depressive syndromes on FM patients are still scarce. For example, it is well-known that stressful life events play a major role in the onset of MDD. In particular, severe acute life events that possess a high degree of threat and unpleasantness, such as the death of a spouse or loss of an important job, have been found consistently to precede the onset of depression (Hammen, 2005, Kessler, 1997, Monroe et al., 2001, Paykel, 2003). However, no studies have examined the association between life stress and depression in patients with FM.

Aim of the study is to investigate the prevalence and clinical correlates of depressive symptoms in patients with FM, and to evaluate the impact of these comorbid depressive symptoms on pain perception and quality of life of FM patients.