Background A large body of studies supports the concept of a frequent comorbidity between chronic pain conditions and psychological distress/disorders, especially depression. However, most of the studies have focused on specific chronic pain conditions and not on the potential differences or similarities between them.
Objectives We aimed to explore the prevalence and severity of depressive symptoms, tension/anxiety (TA), anger/hostility (AH) and fatigue/inertia (FI) among fibromyalgia (FM) and rheumatoid arthritis (RA) patients and healthy controls (HC).
Methods Participants were recruited at rheumatology and gynecology practices in Coimbra and all met the classification criteria for FM and RA or, in the case of HC, the pre-established criteria of a zero score in the London Fibromyalgia Epidemiological Study Screening. The Portuguese versions of the following measures were completed by all participants: Beck Depression Inventory (BDI-II) and Profile of Mood States (PoMs). The samples' characteristics were examined. Descriptive analyses were performed in order to explore the severity of depressive symptoms across samples according with the recommended cut-off points. Differences between samples with respect to depressive symptoms and mood states was tested for significance via Fisher's Exact test and one-way independent ANOVA.
Results 302 participants composed the total sample [103 FM (34.11%), 98 RA (32.45%) and 101 HC (33.44%)]. Differences between samples were found regarding age (F=30.598; p <.001) and education years (F=25.883; p <.001). 17.5% of FM patients reported severe depressive symptomatology against 3.3% of RA patients and 2.1% of HC. Similarly the percentage of FM patients with moderate depressive symptoms (24.8%) was substantially greater than the percentage of RA patients and HC (7.7% and 4.3% respectively). Both FM and RA patients reported higher levels of mild depressive symptoms (24.7% and 11%), when compared to HC (just 3.2%). The majority of HC (90.4%) reported minimal depressive symptoms, a percentage relatively close to RA patients (78%) but considerably different from FM patients (33%). Fischer's Exact test pointed to significant differences between samples regarding the prevalence of depressive symptoms (p<.001). Further analyses revealed that FM, RA and HC differed significantly in the mean scores of BDI-II and its dimensions, with FM patients scoring higher than RA and HC. No significant differences were found between the latter two, except for the somatic/anxiety dimension, with RA patients scoring higher than controls. Significant differences between samples were also found for TA, AH and FI. In all of these dimensions, FM patients scored significantly higher than RA and HC. Once more, RA patients and HC did not differ significantly in the mean scores of PoMS dimensions.
Conclusions Results revealed that FM participants not only evidenced more depressive symptoms than RA patients and HC but also greater levels of TA, AH and FI. In turn, RA patients present scores that are, overall, similar to those of HC. Such findings reinforce not only the extreme emotional suffering that FM patients experience but also the need for interventions designed to manage depressive/anxious symptoms and emotion regulation difficulties.
Disclosure of Interest None declared