Impact of vascular risk factors on clinical outcome in elderly patients with depression receiving electroconvulsive therapy

Background: Although electroconvulsive therapy (ECT) is a highly effective, safe, and well-tolerated antidepressant treatment for late-life depression (LLD), there is large variability in response rates across individuals. We hypothesized that these variations would be in part explained by the level of vascular risk in this population. We therefore compared response rates to ECT in patients with LLD presenting with or without vascular risk factors (VRF). Methods: 52 patients with LLD (age > 55) who received a course of ECT were separated into 2 groups according to the presence of VRF (n = 20) or not (n = 32). Framingham score (10-year risk for developing a coronary heart disease) was calculated for each patient. Our primary outcome was the number of responders to ECT in each group (defined as at least 50% decrease of the Montgomery-angstrom sberg Depression Rating Scale score following ECT course). Scores at the self-rated Beck Depression Inventory are also reported. Results: Patients with VRF presented significant lower response rates to ECT (12 out of 20; 60%) than patients without VRF (30 out of 32; 94%; p = 0.004). A negative correlation was found between Framingham score and changes in depression scores pre/post ECT (r =-0.42; p = 0.0039). Limitations: Our study was limited by sample size and retrospective design. Conclusion: Patients with LLD and VRF showed lower response rates to ECT than those without VRF. The more the VRF increased, the less the antidepressant effect of ECT was observed. Results are discussed in light of the role of apathy in clinical response to ECT.