Patients with treatment-resistant depression (TRD) do not respond sufficiently to several consecutive treatments for major depressive disorder. Deep brain stimulation (DBS) is a promising treatment for these patients, but presently placebo effects cannot be ruled out.
To assess the efficacy of DBS of the ventral anterior limb of the internal capsule (vALIC), controlling for placebo effects with active and sham stimulation phases.
Design, Setting, and Participants
Twenty-five patients with TRD from 2 hospitals in the Netherlands were enrolled between March 22, 2010, and May 8, 2014. Patients first entered a 52-week open-label trial during which they received bilateral implants of 4 contact electrodes followed by optimization of DBS until a stable response was achieved. A randomized, double-blind, 12-week crossover phase was then conducted with patients receiving active treatment followed by sham or vice versa. Response and nonresponse to treatment were determined using intention-to-treat analyses.
Deep brain stimulation targeted to the vALIC.
Main Outcomes and Measures
The change in the investigator-rated score of the 17-item Hamilton Depression Rating Scale (HAM-D-17) was the main outcome used in analysis of the optimization phase. The primary outcome of the crossover phase was the difference in the HAM-D-17 scores between active and sham DBS. The score range of this tool is 0 to 52, with higher scores representing more severe symptoms. Patients were classified as responders to treatment (≥50% decrease of the HAM-D-17 score compared with baseline) and partial responders (≥25 but <50% decrease of the HAM-D-17 score).
Of 25 patients included in the study, 8 (32%) were men; the mean (SD) age at inclusion was 53.2 (8.4) years. Mean HAM-D-17 scores decreased from 22.2 (95% CI, 20.3-24.1) at baseline to 15.9 (95% CI, 12.3-19.5) (P = .001), Montgomery-Åsberg Depression Rating Scale scores from 34.0 (95% CI, 31.8-36.3) to 23.8 (95% CI, 18.4-29.1) (P < .001), and Inventory of Depressive Symptomatology–Self-report scores from from 49.3 (95% CI, 45.4-53.2) to 38.8 (95% CI, 31.6-46.0) (P = .005) in the optimization phase. Following the optimization phase, which lasted 51.6 (22.0) weeks, 10 patients (40%) were classified as responders and 15 individuals (60%) as nonresponders. Sixteen patients entered the randomized crossover phase (9 responders [56%], 7 nonresponders [44%]). During active DBS, patients scored significantly lower on the HAM-D-17 scale (13.6 [95% CI, 9.8-17.4]) than during sham DBS (23.1 [95% CI, 20.6-25.6]) (P < .001). Serious adverse events included severe nausea during surgery (1 patient), suicide attempt (4 patients), and suicidal ideation (2 patients).
Conclusions and Relevance
Deep brain stimulation of the vALIC resulted in a significant decrease of depressive symptoms in 10 of 25 patients and was tolerated well. The randomized crossover design corroborates that vALIC DBS causes symptom reduction rather than sham.
trialregister.nl Identifier: NTR2118