Depression in rheumatoid arthritis patients: demographic, clinical, and psychological predictors

Abstract

Objective

To confirm the prevalence of depression in a sample of rheumatoid arthritis (RA) patients; to identify the most significant predictors of depression in RA and to explore patients attitudes to medication in relation to depression.

Methods

A cross-sectional survey was used to collect data from 134 RA patients (77% female, 23% male). Participants were divided into depressed and nondepressed groups based on their scores on the Center for Epidemiological Studies-Depression (CES-D) scale. Discriminant analysis was conducted to identify the predictors that would best categorise patients into those two groups.

Results

Twelve predictors correctly classified 80% of patients into depressed or nondepressed groups. The strongest predictors of depression were high tension and low self-esteem followed by the perceived impact of RA, fatigue, passive coping, pain, and physical disability. Other predictors included medication effectiveness and importance as well as perceived lack of control over pain.

Conclusion

Both physical and psychological factors have an impact on depression in RA. The key predictors identified in this study need to be considered within the regular RA management as possible cues to depression development.

Introduction

Rheumatoid arthritis (RA) is a chronic, painful, and debilitating musculoskeletal condition with depression being its common comorbidity. In this population, the prevalence of depression ranges from 13% to 20% based on psychiatric assessments and considerably higher when based on self-report assessments [1], [2]. The aetiology of depression in RA appears to be a complex multitude of interactions between clinical, demographic, and psychological factors.

In a meta-analysis of 12 studies, Dickens et al. [3] found that depression was significantly more common among RA patients than healthy individuals and was influenced by the levels of pain but not demographic factors. However, other studies have found that younger RA patients [4], unmarried [5], [6] and less educated [7], [8], had higher levels of depression.

Pain is the primary indicator of health perceptions of patients and clinicians [9], and while it is seen as largely a sensory experience, there is a growing, albeit causally unclear, body of research that suggests a strong link between pain and depression. Some studies suggest that pain leads to depression [10], [11], while others suggest that depression leads to pain [12], [13]. Our recent series of cross-sectional and longitudinal studies found depression to be mostly independent of pain and predicted by physical disability [14], [15] with similar findings reported elsewhere [6], [16]. The relationship between physical disability and depression is further influenced by the level of importance attached to specific physical activities at risk or lost due to RA (i.e., leisure and social functions) [17].

Apart from the impact of demographic and clinical factors, other psychological factors have been found to closely relate to depression. Maladaptive coping in particular appears to be a strong predictor of depression [10], [14], [15]. It is closely linked with a sense of helplessness, which has been found to mediate the relationship between physical disability, maladaptive coping, and depression [14]. Depressed RA patients view their condition as more serious, report more physical symptoms, and feel more helpless about their health outcomes even when controlling for RA severity [18]. The sense of helplessness, negative illness beliefs, and use of maladaptive coping may influence health-seeking behaviours and the use of medical services [19]. Furthermore, it has been reported that depressed RA patients are less compliant with medication [20], but other studies have found no evidence for it [21].

Clearly, a number of demographic, clinical, and psychological factors are implicated in depression among RA patients and reflect the biopsychosocial model of illness [22]. These factors have been explored across a number of studies but usually only a few at a time, which has provided disjointed evidence of their association with depression. The aim of this study is to address this limitation by evaluating a broader range of clinical, demographic, and psychological factors at a given time as a means of determining the most potent predictors of depression in RA.

Specifically, the purpose of this study was to:

• confirm the prevalence of depression in a sample of RA patients,

• explore RA patients' attitudes to medication and their relationship to depression,

• identify the most significant demographic, clinical, and psychological factors associated with depression among RA patients, and

• explore elements of the perceived RA impact and their relation to depression.

Based on the previous research discussed above, it is hypothesised that:

• depressed RA patients will report higher levels of pain, physical disability, and fatigue compared to nondepressed RA patients;

• depressed RA patients will report higher levels of tension and maladaptive coping;

• RA patients will differ in terms of their levels of self-esteem and beliefs about their control over pain, with both of these concepts being closely linked to depression;

• in view of the knowledge that depressed RA patients differ in their compliance with medication and satisfaction with its effectiveness, it is expected that there will be significant differences in their attitudes to medication compared to nondepressed RA patients; and

• based on the close link between the levels of pain, physical disability, and depression, it is expected that depressed RA patients will experience the perceived impact of RA across various life arenas (physical, psychological, and social) to be more adverse than nondepressed RA patients.