Home-based low-field magnetic stimulation as an adjunctive treatment for bipolar depression: A randomized double-blind study.

BACKGROUND

Bipolar depression (BD-D) is associated with high morbidity and suicide risk, yet effective non-pharmacological interventions remain limited. Low-field magnetic stimulation (LFMS), an ultra-low intensity whole-brain neuromodulation, offers potential for home-based therapy. This first randomized controlled trial (RCT) evaluated repeated home-based LFMS efficacy and safety in BD-D.

METHODS

Sixty patients with ICD-10-defined bipolar depression (current depressive episode) were randomized to adjunctive active LFMS or sham stimulation (1:1), delivered twice daily for 2 weeks (28 sessions) using a chip-card blinded device. All participants maintained stable lithium. Primary outcome was change in clinician-rated Hamilton Depression Rating Scale-17 (HAMD-17) from baseline to Week 6. Secondary outcomes included self-reported Quick Inventory of Depressive Symptomatology (QIDS-SR16), and safety (affective switches).

RESULTS

In the full analysis set (FAS, n = 51), HAMD-17 improvements did not differ between LFMS and sham at any timepoint (Week 6: Δ - 0.27, 95% CI: -1.93 to 1.39; P = 0.7427). However, LFMS significantly improved self-reported depression (QIDS-SR16) at Week 4 (Δ1.79, 95% CI: 0.16-3.43; P = 0.0319) and Week 6 (Δ1.83, 95% CI: 0.30-3.36; P = 0.0200). Baseline anxiety (GAD-7) was lower in the LFMS group (P < 0.05), though adjusted in analyses. Mood switch events occurred in both groups (one each). Safety analysis revealed no severe treatment-related adverse events.

CONCLUSIONS

Although home-based LFMS failed to outperform sham on clinician-rated depression, it proved highly feasible and safe while suggesting possible subjective symptom benefits. This divergence emphasizes the need to include subjective endpoints in neuromodulation trials. Future studies should optimize LFMS parameters and target subjective symptom domains in BD-D.

TRIAL REGISTRATION: This study was registered at a Chinese drug clinical trial institution under the registration number ChiCTRUE-INR-17013338, Date: 2017-11-10.