Depression and the Risk of Psoriatic Arthritis Among Patients with Psoriasis: A Population-Based Cohort Study

Ryan Lewinson^1,2, Isabelle Vallerand^1,3, Mark Lowerison³, Laurie Parsons⁴, Alexandra Frolkis^1,3, Gilaad Kaplan^3,4, Andrew Bulloch^3,5,6, Scott Patten^3,5 and Cheryl Barnabe^3,4, ¹Leaders in Medicine Program, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada, ²Biomedical Engineering Program, Schulich School of Engineering, University of Calgary, Calgary, AB, Canada, ³Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada, ⁴Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada, ⁵Department of Psychiatry, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada, ⁶Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada

Meeting: 2016 ACR/ARHP Annual Meeting

Date of first publication: September 28, 2016

Keywords: depression, Epidemiologic methods, Inflammation, psoriasis and psoriatic arthritis

Session Information

Date: Tuesday, November 15, 2016

Title: Epidemiology and Public Health - Poster III

Session Type: ACR Poster Session C

Session Time: 9:00AM-11:00AM

Depression and the Risk of Psoriatic Arthritis among Patients with Psoriasis: A Population-based Cohort Study

Background/Purpose: The factors that contribute to the development of psoriatic arthritis (PsA) among patients with psoriasis are not well known. Individuals with psoriasis are at increased risk of developing major depressive disorder (MDD), and it has been suggested that systemic inflammation associated with immune activation to external stressors/exposures may be a possible mechanism for PsA. Our objective was to determine if MDD confers an independent risk towards the development of PsA among patients with psoriasis.

Methods: Newly diagnosed cases of psoriasis were identified in adults from The Health Improvement Network (THIN) database between 1987 and 2012. The exposure was incident diagnosis of MDD among those with psoriasis. The primary outcome was development of PsA. Cox proportional-hazards models were used to estimate the hazard ratio for the development of PsA. Age, sex, medical comorbidities, socioeconomic status, obesity status, smoking status, alcohol use and psoriasis severity (defined by use of therapies intended for moderate-severe psoriasis) were assessed as effect modifiers and confounders.

Results: In total, 73,447 cases of incident psoriasis were identified, of which 5216 (7.1%) developed MDD. Those that developed MDD were more likely to be younger, female, current smokers, with at least one comorbidity, socially deprived and with moderate-severe psoriasis, and less likely to be obese or alcohol users, (all p-values <0.0001). Among all psoriasis patients, 1466 (2.0%) developed PsA during the observation period. There was no evidence for effect modification by any of the covariates (p=0.368). Individuals with psoriasis who developed MDD were at significantly greater risk of subsequently developing PsA (HR 1.55, 95%CI 1.27–1.90, p<0.0001) compared to those who did not develop MDD, when adjustments were made for age and sex. This association remained significant after adjusting for all covariates (HR 1.34, 95%CI 1.02–1.75, p=0.034) (Table 1, Figure 1).

Conclusion: MDD significantly increased the risk of developing PsA among individuals with psoriasis. Heightened attention to screening for and managing MDD in patients with psoriasis may reduce PsA incidence.

Financial and Commercial Disclosures: This study was supported by a CIHR-Leo Pharma Studentship in Psoriatic Disease through the Canadian Association of Psoriasis Patients. Funding sources played no role in study design, analysis or abstract preparation.

Conflicts of Interest: None of the authors have any conflicts of interest.

Table 1. Hazard ratios for the risk of psoriatic arthritis associated with depression among patients with psoriasis are shown in unadjusted and adjusted models.

Model	Hazard Ratio (95% CI)	P-value

Unadjusted Model
Depression	1.56 (1.28 to 1.90)	<0.0001

Age and Sex Adjusted Model
Depression	1.55 (1.27 to 1.90)	<0.0001
Age	0.81 (0.73 to 0.90)	<0.0001
Sex	1.15 (1.04 to 1.28)	0.006

Multivariable Adjusted Model
Depression	1.34 (1.02 to 1.75)	0.034
Age	0.66 (0.58 to 0.76)	<0.0001
Sex	1.23 (1.08 to 1.40)	0.002
Obesity Status	1.63 (1.42 to 1.88)	<0.0001
Smoking Status	0.90 (0.82 to 0.99)	0.028
Alcohol Use	0.98 (0.82 to 1.16)	0.788
Charlson Comorbidity Index	0.90 (0.82 to 0.99)	0.034
Townsend Deprivation Index	0.99 (0.94 to 1.04)	0.648
Psoriasis Severity	1.86 (1.62 to 2.14)	<0.0001

Figure 1. Kaplan-Meier failure curves are shown to estimate the proportion of psoriasis patients who developed psoriatic arthritis based on exposure to depression (black) or no exposure to depression (dotted grey).

Disclosure: R. Lewinson, Studentship, 9; I. Vallerand, Studentship, 9; M. Lowerison, None; L. Parsons, None; A. Frolkis, None; G. Kaplan, None; A. Bulloch, None; S. Patten, None; C. Barnabe, None.

To cite this abstract in AMA style:

Lewinson R, Vallerand I, Lowerison M, Parsons L, Frolkis A, Kaplan G, Bulloch A, Patten S, Barnabe C. Depression and the Risk of Psoriatic Arthritis Among Patients with Psoriasis: A Population-Based Cohort Study [abstract]. Arthritis Rheumatol. 2016; 68 (suppl 10). https://acrabstracts.org/abstract/depression-and-the-risk-of-psoriatic-arthritis-among-patients-with-psoriasis-a-population-based-cohort-study/. Accessed .

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