Vortioxetine for the treatment of post-COVID-19 condition: a randomized controlled trial

Hitherto no therapeutic has received regulatory approval for the treatment of post-COVID-19 condition (PCC). Cognitive deficits, mood symptoms and significant reduction in health-related quality of life (HRQoL) are highly replicated and debilitating aspects of PCC. We sought to determine the impact of vortioxetine on the foregoing symptoms and HRQoL in persons living with PCC. An 8-week randomized, double-blind, placebo-controlled study of adults ≥ 18 years of age residing in Canada and who are experiencing symptoms of World Health Organization (WHO)-defined PCC, with a history of confirmed SARS-CoV-2 infection, was conducted. Recruitment began November 2021 and ended January 2023. Of the 200 participants enrolled (487 invited: 121 ineligible and 59 eligible but declined participation; 307 cleared pre-screening stage), a total of 149 participants were randomized (1:1) to receive either vortioxetine (5-20 mg, n = 75) or placebo (n = 74) daily for 8 weeks of double-blind treatment (i.e. end point). The primary outcome was the change from baseline-to-end point in the Digit Symbol Substitution Test. Secondary outcomes included the effect on depressive symptoms and HRQoL, as measured by changes from baseline-to-end point on the Quick Inventory of Depressive Symptomatology 16-item and WHO Wellbeing Scale 5-item, respectively. A total of 68 (90.7%) participants randomized to vortioxetine and 73 (98.6%) participants randomized to placebo completed all 8 weeks. Between-group analysis did not show a significant difference in the overall change in cognitive function [P = 0.361, 95% confidence interval (CI) (-0.179, 0.492)]. However, in the fully adjusted model, a significant treatment × time interaction was observed in favour of vortioxetine treatment with baseline c-reactive protein (CRP) as a moderator (P = 0.012). In addition, a significant improvement in Digit Symbol Substitution Test scores were observed in vortioxetine versus placebo treated participants in those whose baseline CRP was above the mean (P = 0.045). Moreover, significant improvement was obtained in measures of depressive symptoms [P < 0.001, 95% CI (-4.378, -2.323)] and HRQoL [P < 0.001, 95% CI (2.297, 4.647)] in vortioxetine-treated participants and between the treatment groups [depressive symptoms: P = 0.026, 95% CI (-2.847, -0.185); HRQoL: P = 0.004, 95% CI (0.774, 3.938)]. Although vortioxetine did not improve cognitive function in the unadjusted model, when adjusting for CRP, a significant pro-cognitive effect was observed; antidepressant effects and improvement in HRQoL in this debilitating disorder were also noted.