Omega-3 Fatty Acids, Depressive Symptoms, and Cognitive Performance in Patients With Coronary Artery Disease: Analyses From a Randomized, Double-Blind, Placebo-Controlled Trial

Abstract

This trial investigated the efficacy of omega-3 polyunsaturated fatty acid (n-3 PUFA) treatment for improving depressive symptoms and cognitive performance in patients with coronary artery disease (CAD) participating in cardiac rehabilitation. Patients with CAD aged 45 to 80 years were randomized to receive either 1.9-g/d n-3 PUFA treatment or placebo for 12 weeks. Depressive symptoms were measured using the Hamilton Depression Rating Scale (HAM-D, primary outcome) and the Beck Depression Inventory II (BDI-II). Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria were used to identify a depressive episode at baseline. Cognitive performance was measured using a standardized battery for vascular cognitive impairment. In 92 patients (age, 61.7 ± 8.7 y; 76% male, 40% depressed; HAM-D, 6.9 ± 5.9; BDI-II, 12.3 ± 10.9; n = 45 n-3 PUFA, n = 47 placebo), depression decreased (HAM-D, F3,91 = 2.71 and P = 0.049; BDI-II, F3,91 = 6.24 and P < 0.01), and cognitive performance improved (attention/processing speed, F1,91 = 5.57, P = 0.02; executive function, F1,91 = 14.64, P < 0.01; visuospatial memory, F1,91 = 4.01, P = 0.04) over cardiac rehabilitation. Omega-3 PUFA treatment increased plasma eicosapentaenoic acid (F1,29 = 33.29, P < 0.01) and docosahexaenoic acid (F1,29 = 15.29, P < 0.01) concentrations but did not reduce HAM-D (F3,91 = 1.59, P = 0.20) or BDI-II (F3,91 = 0.46, P = 0.50) scores compared with placebo. Treatment did not improve cognitive performance; however, n-3 PUFAs significantly increased verbal memory compared with placebo in a subgroup of nondepressed patients (F1,54 = 4.16, P = 0.04). This trial suggests that n-3 PUFAs do not improve depressive and associated cognitive symptoms in those with CAD. The possible benefits of n-3 PUFAs for verbal memory may warrant investigation in well-powered studies.

FIGURE 1

The course of depressive symptoms measured by HAM-D total scores during 12 weeks of CR in n-3 PUFA–treated and placebo-treated patients. The solid line represents the n-3 PUFA–treated group, and the dashed line represents the placebo-treated group. Error bars represent the standard error. Hamilton Depression Rating Scale scores in this figure (y-axis) are estimates adjusted for the included covariates: age, baseline sMMSE, ACE inhibitor use, acetylsalicylic acid use, and diabetes mellitus.