Prevalence of personality disorders in patients with fibromyalgia: a brief review

Abstract

Fibromyalgia (FM) is a complex musculoskeletal pain disorder characterized by widespread pain, fatigue, and other functional symptoms. Patients with FM are frequently affected by psychiatric disorders. Clinicians typically observe certain personality characteristics or traits associated with FM, but there is still a lack of studies about personality disorders (PDs) in patients with FM. Aim of our brief review is to summarize the literature to date on prevalence of PDs in FM. We searched the PubMed electronic database for all articles up to 1 February 2017, and identified a number of reports about prevalence of PDs in patients with FM. Most of studies show that the proportion of PDs diagnosed in patients with FM appears far greater than that found in the general population. We suggest that is very useful to evaluate PDs in patients with FM systematically, in order to improve the understanding, assessment, and treatment of this clinical condition.

Introduction

Fibromyalgia (FM) is a common and complex musculoskeletal pain disorder, characterized by long-lasting widespread pain and abnormal tenderness, associated with variable stiffness, fatigue, poor quality of sleep, cognitive disturbances, and psychological distress (Wolfe et al., 1990; Mease et al., 2009). A recent review by Queiroz (2013) found that the global mean prevalence of FM in the general population was 2.7%, and that the mean rate was 3.1% in the Americas, 2.5% in Europe, and 1.7% in Asia. The 1990 diagnostic criteria proposed by the American College of Rheumatology estimate a female to male ratio of 7:1 (Clauw, 2014). The diagnostic criteria are still a matter of debate, and FM continues to be particularly difficult to diagnose and treat (Rose et al., 2009).

Clinicians should be familiar with the signs and symptoms of FM and know that there are certain conditions associated with FM (Jahan et al., 2012). For example, a substantial lifetime psychiatric comorbidity in patients with FM has been found, suggesting that FM might share underlying pathophysiologic associations with some psychiatric disorders (Arnold et al., 2006). Psychological, behavioural, and social issues have been shown to affect the pathogenesis of FM and complicate its treatment (Fu et al., 2015). Comorbid psychiatric disorders include major depressive disorder, generalized anxiety disorder, obsessive-compulsive disorder, and post-traumatic stress disorder (Clauw, 2014). In our opinion, personality disorders (PDs) are frequently comorbid with FM too. But, although clinicians typically recognize certain personality characteristics or traits that can be associated with FM (Malin and Littlejohn, 2012), and patients with FM have been described as perfectionist (Herken et al., 2001), introspective, demanding (Amir et al., 2000), and occasionally exhausting to manage (Asbring and Närvänen, 2003), there is still a clear lack of studies about PDs in patients with FM.

The aim of our review article is to narratively summarize the literature to date on PDs in FM and give recommendations for future research directions in order to better understand the role of PDs in the pathogenesis and impact of FM and to improve the management and treatment of this complex, highly impacting disorder. We think that PDs and FM are strictly associated with each other, and that this comorbidity has to be promptly identified during the consultation practice, in order to offer the patients a more holistic health care in this area.

Methods

We searched the PubMed electronic database for all articles up to 1 February 2017, and no initial date was used. Search terms included ‘fibromyalgia’ combined with ‘axis II’ or ‘personality disorder’ or ‘personality disorders’ or ‘personality disordered’. The search included all languages. In total, 37 articles were identified. We selected seven original research reports related to the prevalence of PDs in patients with FM (Martinez et al., 1995; Thieme et al., 2004; Rose et al., 2009; Uguz et al., 2010; Garcia-Fontanals et al., 2014; Gumà-Uriel et al., 2016; Kayhan et al., 2016). We excluded 30 articles, on the basis of the following exclusion criteria: (a) studies unrelated to the topic and (b) letters or general comment papers not reporting research findings. Conference abstracts, doctoral dissertations, and grey literature were not eligible based on reporting PD prevalence. References lists were hand searched for missing papers, but hand searching identified no further reports. Three additional original research reports were included in this review instead, based on our knowledge of the subject (Cerón Muñoz et al., 2010; Pando Fernández, 2011; Fu et al., 2015).

Results and discussion

We identified 10 reports of prevalence of PDs in patients with FM (Martinez et al., 1995; Thieme et al., 2004; Rose et al., 2009; Cerón Muñoz et al., 2010; Uguz et al., 2010; Pando Fernández, 2011; Garcia-Fontanals et al., 2014; Fu et al., 2015; Gumà-Uriel et al., 2016; Kayhan et al., 2016). Among them, six studies were performed in outpatient rheumatology settings (Martinez et al., 1995; Thieme et al., 2004; Uguz et al., 2010; Pando Fernández, 2011; Garcia-Fontanals et al., 2014; Fu et al., 2015), two studies in a primary health care setting (Cerón Muñoz et al., 2010; Gumà-Uriel et al., 2016), one study in an outpatient physical therapy service (Kayhan et al., 2016), and one study in a consultation-liaison psychiatry setting (Rose et al., 2009). Four articles focused on samples of only female patients with FM (Martinez et al., 1995; Thieme et al., 2004; Garcia-Fontanals et al., 2014; Kayhan et al., 2016). A categorical classification system was used for the diagnosis of PDs in eight studies (Thieme et al., 2004; Rose et al., 2009; Cerón Muñoz et al., 2010; Uguz et al., 2010; Pando Fernández, 2011; Fu et al., 2015; Gumà-Uriel et al., 2016; Kayhan et al., 2016). The most used PDs categorical assessment instrument was the Structured Clinical Interview for DSM-III-R (Spitzer et al., 1990) and for DSM-IV (First et al., 1996) (n=4), followed by the ICD-10 International Personality Disorder Examination (Loranger, 1999) (n=3). One study used the Personality Diagnostic Questionnaire-4 (Abdin et al., 2011). As for PDs dimensional assessment, one study used the Temperament and Character Inventory-Revised (Cloninger, 1999), and one study the Kurt Schneider’s (1959) method for the diagnosis of PDs.

Table 1 summarizes the results from the 10 reviewed articles, in descending chronological order. Obsessive-compulsive PD was found to be the most common in three samples (Rose et al., 2009; Uguz et al., 2010; Pando Fernández, 2011), Avoidant PD was the most common in two samples (Fu et al., 2015; Gumà-Uriel et al., 2016), Histrionic PD was the most common in two samples (Cerón Muñoz et al., 2010; Kayhan et al., 2016), and Borderline PD was the most common in one sample (Thieme et al., 2004). Two studies did not report the prevalence of specific PDs (Martinez et al., 1995; Garcia-Fontanals et al., 2014). Most of studies highlight that the most prevalent PDs diagnosed in patients with FM are those belonging to Cluster C disorders (Rose et al., 2009; Uguz et al., 2010; Pando Fernández, 2011; Garcia-Fontanals et al., 2014; Fu et al., 2015; Gumà-Uriel et al., 2016) in the Diagnostic and Statistical Manual of Mental Disorders. Cluster C include three PDs sharing anxious and fearful features (avoidant, dependent, and obsessive-compulsive) (Sadock et al., 2014).

Table 1 Main findings from studies of prevalence of personality disorders in patients with fibromyalgia

FM=fibromyalgia; PD=personality disorder.

Studies conducted on large representative samples of community populations found prevalences of PDs between 13.4 and 14.8% (Torgersen et al., 2001; Grant et al., 2004); a more recent review by Samuels (2011) found that the prevalence of PDs in the general population was between 6 and 13%. Differently, our review shows that the prevalence of PDs in patients with FM ranged from 8.7 to 96.7%, so we can say that the proportion of PDs diagnosed in patients with FM appears far greater than that found in the general population. For example, in our review, the largest sample study included the data from 157 patients with FM participating in a randomized, controlled trial, and showed that 65.0% of the sample had a possible PD (Gumà-Uriel et al., 2016).

PDs appear to be frequent comorbid disorders in patients with FM. Moreover, it has been demonstrated that patients with FM and comorbid-PD have worse functional status and higher direct costs, especially in terms of visits to primary health care and specialists (Gumà-Uriel et al., 2016). Reviewed studies underline a possible link between FM and PDs, but this link has to be further investigated along with neurobiological research to better understand the FM etiopathogenetic mechanisms. What we know so far about FM is that genetics plays a role in the development of the FM as well as in the serotonin and noradrenaline system (Bazzichi et al., 2016). Other neuroendocrine transmitters such as substance P, growth hormone, and cortisol seem to be involved too. Sleep alterations, aberrant pain processing, and a disturbed stress-adaptation response are often found in patients with FM. This all suggests a possible major role for autonomic and neurotransmitters abnormalities and for stress response alterations (Jahan et al., 2012). These pathophysiological mechanisms could be shared with PDs, at least in part.

Several limitations deserve mention in this discussion. Surely, a major limitation of this paper is the decision to perform only a narrative review; the total prevalence of PDs was not pooled together where possible, providing 95% CI and heterogeneity estimates, and the estimated pooled prevalence of specific PDs was not performed to gauge the most common subtype of PD in FM. Another limitation is that some of the reviewed studies used non-categorical assessment methods to determine PDs; specifically, two studies were included who utilized the Temperament and Character Inventory-Revised (Garcia-Fontanals et al., 2014) and Schneider’s method (Martinez et al., 1995) for the diagnosis of PDs. A third limitation lies in the fact that only PubMed electronic database was used for searching, suggesting the possibility of some missing papers.

However, despite the limitations, we believe that this narrative review could add useful information to the literature and the journals readership including practicing clinicians. Prompt diagnosis and treatment of FM and of associated conditions may produce substantial improvement in quality of life of affected patients. Due to the high frequency of the association between FM and psychiatric disorders in general, a careful clinical assessment is warranted to identify FM patients who may also benefit from specific psychotropic medications, and from psychotherapeutic and psychosocial interventions. We suggest that it is very useful to systematically evaluate PDs too in patients with FM, in order to improve the understanding, assessment, and treatment of this complex clinical condition. Knowledge of the core features of PDs may help physicians to recognize, diagnose, and treat affected patients, for example suggesting a specialist’s consultation. Furthermore, we suggest that PDs should be evaluated using validated assessment instruments and not only on the basis of clinician’s judgment, in order to provide a reliable diagnosis. As the symptoms of FM are related to stresses, an optimal treatment needs to be an ongoing process and has to be based on a patient centered approach (Jahan et al., 2012). Patients should participate in developing a care plan, this will help them to focus on positive lifestyle changes limiting anxiety and stress. Therefore, a close multimodal collaboration among general practitioners and specialists from different fields is essential for successful management of patients with FM.