MDD may up risk of psoriatic arthritis among patients with psoriasis
Major depressive disorder (MDD) appears to contribute to a significant increase in the risk of developing psoriatic arthritis (PsA) among patients with psoriasis, a study suggests.
Using the primary care database Health Improvement Network, researchers identified and followed 73,447 patients with psoriasis (median age at diagnosis 49.5 years) for up to 25 years for the development of PsA, the primary outcome of the study. MDD was designated as the primary exposure of interest. The median follow-up duration was 5.1 years.
Of the patients, 7.1 percent developed MDD after a median of 3.1 years from diagnosis of psoriasis. Compared with those who were not diagnosed with MDD, MDD patients were more likely to be younger, female, current smokers, with at least one comorbidity, socially deprived and with moderate-severe psoriasis, but were less likely to be obese or alcohol users (p<0.0001).
On Cox analysis, MDD was associated with an elevated risk of PsA, with psoriatic patients in the MDD cohort being 1.37 (95 percent CI, 1.05 to 1.80) times as likely as their counterparts in the no MDD cohort to subsequently develop PsA (p=0.021). This association was maintained through numerous sensitivity analyses.
The relationship between MDD and elevated PsA risk might have been mediated by negative health behaviours (ie, unhealthy diet and physical inactivity) and increased systemic inflammation. Researchers emphasized that such relationship was not causal as psoriatic patients without MDD also developed PsA, and not all psoriatic patients with MDD developed PsA. “Thus, other risk factors remain to be discovered that also contribute to the development of PsA.”[Am J Prev Med 2016;51:327–335; Brain Behav Immun 2016;51: 29–38].
In light of the 37-percent increase in PsA risk associated with MDD in psoriasis, focus is warranted on preventing and managing MDD in patients with psoriasis.