Exploratory Analysis of the Effects of Celecoxib on Cognitive Function in Vortioxetine-Treated Patients With Major Depressive Disorder in the PREDDICT Study: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Objective: Major depressive disorder (MDD) remains difficult to treat, with many patients resistant to existing treatments or experiencing relapse. Cognitive dysfunction is associated with more severe clinical outcomes. Vortioxetine has shown efficacy in remediating depression-associated cognitive impairment. Anti-inflammatory augmentation of antidepressants is a new strategy in treating depression and has not previously been assessed for effects on cognition in depression. Methods: Exploratory analyses were performed on secondary outcome cognitive data from the PREDDICT parallel-group, randomized, double-blind, placebo-controlled trial at the University of Adelaide (Australia). Participants (N=119) with MDD (validated with Mini -International Neuropsychiatric Interview for DSM-IV) were treated with vortioxetine and celecoxib or vortioxetine and placebo for 6 weeks between December 2017 April 2020. Measures included objective cognition composite scores (Choice Reaction Time, N-Back, Digit Symbol Substitution Test, Trail Making Task Part B), subjective cognition scores (Perceived Deficits Questionnaire), and global cognition composite scores (combined objective and subjective scores) derived from the THINC integrated tool (THINC-it). High-sensitivity C-reactive protein (hsCRP) measured at baseline and week 6 was tested for a predictive relationship with cognitive outcomes. Results: Cognition composite scores demonstrated improvement by week 6 in both treatment groups. However, there was no significant interaction between change over time and treatment group. HsCRP did not have a significant relationship with any tested cognition measures. Conclusions: Both treatment groups showed a reduction in depression- associated cognitive impairment. No superior clinical effect was reported for the add-on celecoxib group. HsCRP was modulated by neither vortioxetine nor add-on celecoxib. Trial Registration: ANZCTR identifier: ACTRN12617000527369