Factors Increasing Risk of Anxiety and Depression in SpA
Information on the factors associated with anxiety and depression in patients with SpA has been scarce. A questionnaire-based Swedish study that sought to shed light on this issue found the associations to be multifactorial, including patient- and disease-related factors. The study used the Hospital Anxiety and Depression Scales (HADS-A and HADS-D) to measure anxiety and depression. It found that higher scores on these scales, as correlated with a higher probability of anxiety and depression, were associated with lower education, more chronic pain problem, more fatigue, lower overall health, lower health-related QoL, lower physical functioning, higher disease activity, and lower self-efficacy. Higher HADS-D scores were also associated with less physical activity. The study authors conclude that since these comorbidities are increased in SpA patients and treatable, they instruments like HADS should be used to screen patients in clinical practice.
Connection Between Pain and Depressive Symptoms in PsA
A 2012 study reported small but consequential evidence supporting a bidirectional relationship between depressive symptoms and pain. However, the strongest predictors of changes in pain, swollen joint counts, and depressive symptoms between visits were scores of the corresponding variables at the previous visit. More previous pain or depression was associated with larger improvements in pain or depressive symptoms, respectively, at subsequent visits, presumably due to treatment decisions. Based on their findings, the authors suggest the potential for improved patient outcomes through a clinical approach that assesses and treats depressive symptoms and pain at each visit.
Impact of Psychological Distress on Quality of Life in PsA and AS
Psychological factors, including anxiety, depressive symptoms, and illness perceptions affect outcomes in rheumatic diseases, but how they affect health-related QoL across disease forms has been unclear. Two studies compared these factors in rheumatoid arthritis (RA) vs PsA and AS, respectively.[2,7] In the PsA study, after adjusting for disease severity and pain in those with PsA, anxiety and concern about bodily symptoms attributed to the illness were independent correlates of QoL. In those with RA, depressive symptoms and concern about disease consequences were independent correlates of QoL. In the AS study, illness concern was the only significant independent correlate of QoL in AS patients, whereas depression and worries about the consequences of the disease were additional correlates in RA. These studies highlight the importance of addressing psychological factors in all arthritis patients and educating them about the potential impact of mood disorders on their symptoms.[2,7]
Sleep Disturbances Mediate Disease and Function in AS
Sleep disturbances have been reported in 15.4% to 80% of AS patients, depending on how sleep disturbances were defined and measured. In an Asian study of 314 patients with AS, 184 were found to be at high risk of sleep disturbances on the Pittsburgh Sleep Quality Index (PSQI), with depression, anxiety, nocturnal pain, and total back pain found to be major contributors of sleep disturbances in these patients. In another study, poor sleep quality (total PSQI score) was positively correlated with increased pain, poor QoL, more depressed mood, higher disease activity, and more mobility restrictions in AS patients. Pain was also found to be an independent contributor to poorer sleep quality (P =.002). These studies indicate a need to better understand sleep disturbances in patients with SpA, including the interrelationship between the demographic- and disease-related variables that can lower quality of sleep in these patients.
Connection Between Inflammation and Depression
Interactions between inflammation and mood disorders have been observed. Psychological stress has been reported to elevate proinflammatory markers, such as C-reactive protein (CRP), tumor necrosis factor (TNF)-α, interleukin (IL)-1b, and IL-6, as well as exacerbate or induce autoimmune diseases by enhancing hypothalamus-pituitary-adrenal axis hyperactivity, leading to T-cell sensitivity of proinflammatory cytokines and subsequent immune dysregulation. Proinflammatory marker levels have also been shown to be predictive of depressive symptoms. In a prospective British occupational cohort study, baseline CRP and IL-6 predicted cognitive symptoms of depression at follow-up; however, baseline symptoms of depression were not predictive of inflammatory markers at follow-up. These findings persisted after adjusting for a variety of patient- and disease-related variables, leading the authors to conclude that inflammation likely precedes the cognitive symptoms of depression.
Impact of Biologics on Depression, Anxiety, and Insomnia
Because depression has been associated with proinflammatory markers, and antidepressants are not always successful in treating depression, there has been considerable interest in examining the effect of TNF-α inhibitors on mood disorders. A systemic meta-analysis reported that use of TNF-α inhibitors led to small reductions in depression (−0.24; 95% confidence interval [CI], −0.33 to −0.14; P <.001) and anxiety (−0.17; 95% CI, −0.31 to −0.02; P =.02) in patients with RA, psoriasis, or AS. However, it was unclear whether depression was mediated by a reduction in TNF-α or resulted from reductions in pain/ disability. An Asian nationwide cohort study of patients with PsA or psoriasis also suggests that TNF-α inhibitor therapy reduce rates of depression and insomnia. In the study, 20% of patients were taking antidepressants before starting a TNF-α inhibitor, and there was a >40% reduction in antidepressant use after biologics therapy for 2 years. More rapid/significant reductions in depression/insomnia were observed in patients on continuous TNF-α inhibitor therapy, aged <45 years, without PsA, and not taking concomitant methotrexate.
Effect of Exercise on Depression Severity in AS
Significant improvements in depression and pain have been reported in AS patients who performed a 20-min home-based exercise routine once daily for 8 weeks compared with wait-listed controls (both measures P <.0001). They also had significant improvements in joint mobility, including cervical flexion, extension, shoulder flexion, abduction, hip abduction, knee flexion, and functional capacity. The patients’ exercise program consisted of 16 movements based on an exercise program recommended by the Spondylitis Association of America.[14,15] Although it is unclear exactly how the exercise routine led to alleviated depression, functional capacity has been reported to be an independent risk factor for psychological disorders; thus, improvement in this measure could have been an important contributor. More studies are needed to assess the impact of exercise on mood disorders in patients with SpA and to determine the best programs for these patients.
Prevalence of Depression in AS
A questionnaire-based study reported clinically significant depressive symptoms in 14.8% of patients with AS (n=55), as defined by a score ≥10 on the Patient Health Questionnaire. A Swedish study that compared the rate of physician-diagnosed depression in a well-defined cohort of AS patients with the general population seeking care reported similar results. During a 13-year observation period, depression was diagnosed in 10% (n=172) of AS patients. The physician-diagnosed depression rate was increased by about 80% in women and 50% in men with AS. More recently, an Asian study reported that AS not only increased the risk of depressive disorder, but of anxiety disorder, and/or sleep disorders. Collectively, these studies highlight the need for psychiatric evaluation and intervention for patients with AS.[2-4]
Spondyloarthritis (SpA) is an umbrella term used to describe a group of chronic inflammatory diseases involving the joints and entheses. Ankylosing spondylitis (AS) is the most common form, affecting 0.2% to 0.5% of the US population. In patients with AS, the spine and vertebrae are typically affected, which can result in back pain, impaired mobility, and reduced work productivity and quality of life (QoL).
Patients with AS and other forms of SpA, such as psoriatic arthritis (PsA), have been found to have a high prevalence of psychological comorbidities, including depression, anxiety, and sleep disturbances, which can further reduce their QoL and adversely affect their outcomes. Therefore, to optimize the care and outcomes of patients with SpA, clinicians must strive to effectively treat the condition and its symptoms while also addressing potential psychological risk factors and comorbidities.