Differential effects of antidepressants on cognition in Alzheimer's disease with depression: A sub-group analysis of an open-label, observational study

BackgroundDepressive symptoms are common in Alzheimer's disease (AD), leading to an increasing use of antidepressants.ObjectiveTo compare the effects of vortioxetine with other conventional antidepressants on cognition in AD patients with depressive symptoms.MethodsThis analysis is a subgroup of a 12-month, prospective, randomized, open-label, parallel-group study involving 108 outpatients receiving either vortioxetine or escitalopram, paroxetine, or bupropion as part of routine care. Data were collected at baseline, 6 and 12 months. Cognitive symptoms were assessed using the Mini-Mental State Examination (MMSE), Attentive Matrices (AM), Coloured Progressive Matrices (CPR), and Digit Span; depressive symptoms using the Hamilton Depression Scale (HAM-D) and the Cornell Scale for Depression in Dementia (CSDD). Results for patients on vortioxetine were compared to those on other antidepressants.ResultsTotal scores on cognitive measures improved in all groups. Improvements versus baseline in MMSE, AM, and CPM were statistically significant in the vortioxetine group (p < 0.001), but not in the other antidepressant groups. Digit Span scores did not differ significantly from baseline. The between-group differences in MMSE, AM, and CPM changes were statistically significant in favor of vortioxetine (p < 0.05), while the Digit Span change showed a trend towards superiority with vortioxetine, but did not reach statistical significance. The between-group differences in HAM-D and CSDD changes were also statistically significant for vortioxetine (p < 0.05).ConclusionsVortioxetine was superior in improving both cognitive and depressive symptoms compared to other antidepressants. Larger studies which may also help to understand whether the beneficial effect observed with vortioxetine was a direct effect or mediated by its specific antidepressant efficacy are required.