Predicting Cognitive Abilities and Treatment Outcome of Major Depressive Disorder in Elderly Patients Using Vortioxetine and Duloxetine Antidepressants

Depression affects up to 35% of the elderly population, and is often called late-life depression. In addition to lowered mood and other symptoms associated with depression, many people with late-life depression also experience subjective and/or observed cognitive impairment. Robust evidence suggests that while cognitive impairment for some people with late-life depression is reversible, there is a substantial proportion of those with impaired cognition that continues to worsen and can progress to dementia. In other words, late-life depression is a risk factor or an early stage of dementia. Evidence regarding the effect of antidepressant treatment on improving cognitive deficiency in late-life depression is mixed, indicating antidepressants may be associated with reduced dementia risk, no effect, or even increased risk of dementia. Previous studies found that vortioxetine, a novel antidepressant with a unique pharmacodynamic profile, had a positive short-term effect on cognition compared to placebo and to duloxetine, another anti-depressant. However, it is unknown whether cognitive ability is related to the effect of the drug or to the effect of improved mood and other depressive symptoms. This study aims to explore whether different baseline cognitive or other depression symptoms predict cognitive treatment outcome, and the association between remission of depression and cognitive improvement. We plan to utilize the data set from the previous study, and perform more detailed and advanced statistical analyses to address these questions. Findings of the study will lead to a deeper understanding of the effect of vortioxetine on cognition in people with late-life depression, and factors predicting cognitive outcome. Given the scale of the problem, this is a very important public health concern. In addition, this study will inform future research of whether antidepressants such as vortioxetine can be used for cognitive improvement and reduce the risk of developing dementia.