ObjectiveVortioxetine, a new antidepressant, has been demonstrated to have effects on depression and cognitive function. This study aimed to investigate the anti-depressive efficacy of vortioxetine through a well-designed double-blind, placebo-controlled study in Alzheimer’s disease (AD) patients, and to confirm the presence of secondary benefits, including the improvement of cognitive function and activities of daily living (ADL).MethodsThe present study included 100 AD patients with depression who were assigned randomly to 12 weeks of daily treatment with either vortioxetine or placebo. The primary efficacy measure was the change in the Cornell Scale for Depression in Dementia score from baseline to 12 weeks. Several secondary efficacy measures were evaluated, including the Korean version of the Short form of Geriatric Depression Scale and several cognitive function domains. The safety and tolerability of vortioxetine were also assessed. We performed modified intention-to-treat analysis using mixed modeling (the Mixed Models for Repeated Measures).ResultsThere was no statistically significant difference between the two groups in terms of depressive symptoms, cognitive functions, and ADL. Further, the percentage of adverse events and drug discontinuation between the vortioxetine and placebo groups was similar.ConclusionOur results suggest that vortioxetine might not be effective in reducing depressive symptoms or cognitive impairment in AD patients with depression. However, general drug tolerance and patient safety were similar to those of placebo. Thus, additional studies are needed to replicate the effectiveness and tolerability of vortioxetine in AD patients with depression.