Depression, anxiety and adjustment disorder among patients with psoriasis receiving systemic agents: A retrospective cohort study in Quebec, Canada

Abstract Introduction Patients with psoriasis are at risk of depression, anxiety and adjustment disorder (DAAD). Randomized control trials reported improvement in depression and anxiety symptoms among patients with psoriasis receiving tumour necrosis factor inhibitors and ustekinumab (TNFi/UST) versus placebo and conventional systemic agents (CSA). The risk of DAAD among TNFi/UST versus CSA users was not assessed in real‐world settings. Objective To compare DAAD incidence among patients with psoriasis using CSA and subsequently received (vs. not) TNFi/UST. Methods We conducted a retrospective cohort study using the province of Quebec health administrative databases (1997–2015). Among adult patients with a diagnosis of psoriasis and initiating a CSA, we included those who later initiated a TNFi/UST, as a switch or add‐on, at the date of their first prescription fill (index‐date). We also included TNFi/UST nonusers at a date chosen to match the time between the first CSA and the index date of a random TNFi/UST user. TNFi/UST nonusers were classified into current or previous CSA users according to their last CSA received in the 90 days before or after their index date. Marginal structural Cox regression models weighted by the inverse probability of exposure compared the risk of DAAD between TNFi/UST, current and previous CSA users. Additional analyses were conducted by age group and sex. Results Our cohort included 1333 patients with psoriasis: 183 TNFi/UST users, 625 current CSA users and 525 previous CSA users. TNFi/UST users were at a lower risk of DAAD versus previous CSA users (hazard ratio 0.48, 95% confidence intervals: 0.28–0.94). The reduction in risk among TNFi/UST users was not statistically significant versus current CSA users. Similar results were observed across different age groups and sex. Conclusion Among patients with psoriasis receiving CSA, those who were subsequently dispensed TNFi/UST were at a lower risk of DAAD compared to those who did not receive these agents.