Mental Health Screening in Psoriatic Arthritis Patients
Studies have shown that psoriatic arthritis (PsA) does increase the psychological burden of psoriasis, however, there isn’t enough data about how it affects a person’s overall mental health. Psoriasis patients with comorbid psoriatic arthritis (PsA) are a subpopulation with distinct clinical needs and putatively increased but an under-investigated psychological burden. It’s still unclear whether the effects of PsA on patients’ mental health can be attributed to their levels of pain.
Depression and Psoriatic Arthritis
Depression is often overlooked in both dermatology and primary care settings. Many cases of depression also remain undiagnosed in at-risk populations with moderate-to-severe psoriasis. Since depression and anxiety are primary contributors to disability and are associated with adverse outcomes in psoriasis, it is vital to understand their relationships with psoriatic disease and develop prevention and management algorithms for high-risk groups. A major failure in depression management, even in populations at risk, is the fact that depression often remains undiagnosed. Dermatologists may not recognize depression in over half of the cases. Screening for mental health burdens such as anxiety and depression could aid this patient population in getting medical intervention sooner.
The Study
The study seeks to understand whether PsA is associated with higher depression and anxiety in moderate-to-severe psoriasis. It also explores the levels of pain and the prevalence of undiagnosed and untreated depression.
Methods
The researchers analyzed baseline data from the British Association of Dermatologists Biologic and Immunomodulators Register (BADBIR) participants completed the Hospital Anxiety and Depression Scale (HADS). BADBIR is a prospective cohort enrolling patients with moderate-to-severe psoriasis in over 160 sites in the United Kingdom and the Republic of Ireland. Data until May 2020 were used in this study. The researchers included all participants who completed the baseline Hospital Anxiety and Depression Scale (HADS). Baseline patient characteristics, including sociodemographic and clinical data, were obtained using a combination of patient interviews, examination, and hospital records screening performed by a trained professional.
Outcome Measures
The study’s primary outcome measure was the HADS. a validated screening tool for depression and anxiety in patients with physical illness. HADS was introduced as a baseline assessment in BADBIR in 2019. The researchers reported two definitions for depression and anxiety, using two thresholds (≥8 and ≥11) for each HADS subscale. A cut-off ≥8 in the HADS-Depression subscale (HADS-D) shows optimal psychometric properties for identifying major depression (specificity/sensitivity: 0.82/0.74). A cut-off ≥11 is more specific but less sensitive (0.92/0.56).10 There is less evidence on the HADS-anxiety subscale (HADS-A); a meta-analysis found a sensitivity/specificity of 0.78/0.74 for identifying generalized anxiety disorder (GAD) using scores ≥8.
Complementarily to these definitions, the study reports overall HADS-subscale scores as indicators of depressive and anxiety symptom burden for comparative purposes. Three severity bands have been proposed for each HADS subscale (8–10: mild, 11–14: moderate, 15–21: severe depression/anxiety).To define an existing diagnosis of depression, the researchers used the reported Medical Dictionary for Regulatory Activities (MedDRA) High-Level Term ‘Depressive disorders’. The researchers also examined the reported preferred terms for all psychiatric disorders in the sample to reduce misclassification bias.
Data analysis
The researchers used chi-square tests, t-tests and Mann-Whitney U tests where appropriate to compare baseline characteristics between the groups. They also investigated associations of PsA with depression and anxiety prevalence using logistic regression and controlling for age, gender, ethnicity, and physical comorbidities (as having at least one of the following: cardiovascular disease, cancer, inflammatory bowel disease, endocrine, other musculoskeletal, severe systemic, central nervous system disease or severe chronic infections), psoriasis severity measured with the Psoriasis Area and Severity Index (PASI), and Body Mass Index (BMI).
The researchers used t-tests to investigate differences in mean HADS-subscale scores between the groups; and linear regression models to control for confounders in the associations between HADS scores and PASI. For analysis, they excluded PASI scores according to a set of criteria, which took account of the temporal relationship of PASI to the HADS assessment and the start of treatment.
Results
707 patients (n = 540 with psoriasis only; n = 167 with psoriatic arthritis) were included. Depression prevalence was higher in patients with psoriatic arthritis, when a HADS-depression subscale cut-off ≥8 was used (33% vs. 23%, adjusted Odds Ratio [OR] (95% Confidence Intervals [CI]) = 1.64 (1.09–2.45)), but did not differ using the HADS cut-off ≥ 11. Anxiety prevalence was higher among PsA patients, regardless of HADS cut-off (cut-off ≥11: adjusted OR (95% CI) = 1.62 (1.07–2.45)). Pain fully mediated the effect of PsA on depression and anxiety in psoriasis. 53.6% of participants identified as depressed did not have a known psychiatric disorder; two-thirds of depressed participants were not treated.
Compared to the previous report from a single tertiary center, depression prevalence was overall lower in this BADBIR sample for patients with PsA (11.9% vs. 32.5% previously; HADS cut-off ≥11), but similar among patients with psoriasis only (11.5% vs. 11.6% previously). In the present study, the association with PsA was only statistically significant when the lower HADS-D depression cut-off of 8 was used, but not using HADS-D ≥11, in contrast to both findings and those of McDonough et al.
This may be explained by differences in population characteristics. BADBIR participants were recruited from dermatology centers, whereas most PsA patients in these two previous reports were recruited from rheumatology clinics. It is plausible that the BADBIR cohort has milder or currently less active PsA. PASI-assessed psoriasis severity was higher in BADBIR, but chronic disease burden was less pronounced (15.5% of participants had tried biologics before enrolment compared to 79% of participants in our previous study). Furthermore, we here include geriatric patients (8.6% of the sample) in contrast to our last working-age sample.
Further explanation could be that the overrepresentation of depression in PsA predominantly concerns milder depression forms; or that may not have detected a true, smaller difference for severe depression due to its generally lower prevalence. This could also explain findings in the wider cohort, where the groups differed for depression history, in contrast to our HADS-completing sample. Although this cannot rule out the effects of depression on non-completion, the main reason for HADS missingness was the later introduction of the measure in the registry.
Final Thoughts
PsA comorbidity in psoriasis is associated with higher anxiety. Its link with depression appears to be robust when milder depressive syndromes are included, but less consistent for higher-threshold depression definitions. Depression remains unrecognized and untreated in over half of moderately-to-severe psoriasis patients. Routine depression and anxiety screening is recommended for psoriasis and PsA. Psoriatic arthritis comorbidity may increase depression and anxiety in psoriasis through painful experience.