Which Cognitive Domains are Improved by Treatment with Vortioxetine?

BACKGROUND: These post hoc analyses evaluated vortioxetine efficacy on cognitive dysfunction in depression. Data were from a double-blind, randomized, fixed-dose, placebo-controlled, 8-week depression study in adults aged 18–65 years (n = 602) with DSM-IV–defined major depressive disorder (MDD). Subjects were randomized (1:1:1) to vortioxetine 10mg/day or 20mg/day or placebo. METHODS: Cognitive function was assessed at baseline, Week 1 (10mg/day only) and Week 8 using Digit Symbol Substitution Test (DSST) number of correct symbols, Rey Auditory Verbal Learning Test, Trail Making Test, Stroop test, Simple Reaction Time, and Choice Reaction Time tests. The cognition variables were standardized and used for constructing composite Z-scores for the cognitive domains of executive function, attention/speed of processing, and memory. RESULTS: At Week 1, vortioxetine 10mg/day separated from placebo for attention/speed of processing (standardized composite Z-score = 0.21; p = 0.0238) and DSST number of correct symbols (standardized effect size = 0.18; p = 0.0458) and for executive function (standardized composite Z-score = 0.20; p = 0.0274). At Week 8, vortioxetine 10mg/day and 20mg/day separated from placebo for executive function and attention/speed of processing, with standardized composite Z-scores ranging from 0.35 to 0.49 (all p < 0.01). Standardized composite Z-scores for memory were 0.31 (p = 0.0036, 10mg/day) and 0.22 (p = 0.0349, 20mg/day). Standardized effect sizes for DSST were 0.51 (p < 0.0001, 10mg/day) and 0.52 (p < 0.0001, 20mg/day). Results are limited by the post hoc nature of the analyses and the absence of an active reference in the original study. CONCLUSIONS: Vortioxetine (10 and 20mg/day) had a multi-domain beneficial effect on cognitive performance, as evidenced by improvements in measures of executive function, attention/speed of processing, and memory. The effect on the DSST may be due to improvements in several cognitive skills.