The Effectiveness of Electroconvulsive Therapy for Major Depressive Disorder According to Patient Self-Report

BACKGROUND: Major depressive disorder (MDD) is a common, typically recurrent, often chronic, and disabling disorder affecting approximately 14 million adults in the United States (US) each year. Electroconvulsive therapy (ECT) is a neurostimulation therapeutic intervention that is highly effective and most often used to treat certain psychiatric conditions, in particular MDD. Despite the proven effectiveness of using ECT to treat MDD there have been no other studies that have addressed methods of assessing the severity of depressive symptoms using patient self report instrument. SUBJECTS: Ninety-four participants, comprised of 58 (61.7%) females and 36 (38.3%) males who ranged from 20 to 85 years of age (M=51.76, SD=15.19) participated in this study. All subjects had a diagnosis of MDD and were treated with ECT over an average of 11 sessions on an inpatient or outpatient basis at the UT Southwestern Medical Center Zale Lipshy University Hospital (ZLUH, Dallas, TX). METHOD: The 16-item self-report version of the Quick Inventory of Depressive Symptomatology (QIDS-SR16) measure was used to determine the effectiveness of ECT in treating MDD. Data was acquired at baseline and after the end of the acute ECT treatment course. Paired t-tests were applied to determine if there were significant depression improvements and effect size (r) was calculated to determine the effect size between pre- and post- treatment scores on the Quick Inventory of Depressive Symptomatology-Self Report₁₆ total score and each domain score. RESULTS: The overall baseline average total score of QIDS-SR₁₆ (M=18, SD=4.34) for the study sample was in the severe range. After completion of the acute ECT course, the QIDS-SR₁₆ total score on average significantly decreased to the mild range (M=7.18, SD=4.74). The overall total QIDS-SR₁₆ score had a large effect size (E.S.) (E.S. (r) =.91; t = 20.98, df = 93, p =. 000). Consistent with this, the domain scores also had a large effect size. The E.S. (r)-scores from greatest to the least for the domain scores are mood (E.S. (r) =.88; t = 17.58, df = 93, p =.000), suicide (E.S. (r) =.83; t = 9.19, df = 93, p =.000), fatigue (E.S. (r) =.78; t = 12.13, df = 93, p=.000), self-outlook (E.S. (r) =.75; t = 11.07, df = 93, p =.000), concentration (E.S. (r) =.72; t = 10.03, df = 93, p =.000), sleep (E.S. (r) =.68; t = 8.96, df = 93, p =.000), loss of interest (E.S. (r) =.68; t = 14.58, df = 93, p = .000), psychomotor(E.S. (r) =.65; t = 8.35, df = 93, p = .000), and appetite change (E.S. (r) =.62; t = 7.74, df = 93, p = .000). Data revealed few differences between electrode configuration placements. The sad mood and suicide domains resulted in a greater decline in symptom ratings than the remaining seven domains over the course of an acute ECT treatment. DISCUSSION: The findings of the study are consistent with prior research suggesting that ECT is an effective treatment for MDD. Specifically, depressive symptoms as rated by self report showed a significant decrease from baseline to completion of the acute ECT course. The data from the QIDS-SR16 revealed an overall marked improvement in total depression severity, and in specific depressive domains including mood, suicidal ideation, energy, self-outlook and concentration/decision making. IMPLICATIONS: The research has some limitations. the present study only recruited patients from one hospital, which may limit the generalizability of the findings. This was a naturalistic study based on a clinical database. There could have been possible comorbidities (both medical and neuropsychiatric) that could have affected outcome. The switch of electrode placement was non-systematic and based on physician judgment and not based on the study’s criteria.