Title : Combining repetitive transcranial stimulation with transcranial direct current stimulation for psychiatric conditions: A scoping review
Abstract:
Background: Repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) have been thoroughly explored in the treatment of various psychiatric disorders and neuropsychiatric symptoms. There is an increasing number of studies exploring the combination of both modalities to treat mental illness. In this scoping review, we summarize all existing studies that have combined rTMS and tDCS to remedy psychiatric disorders and symptoms.
Methods: We comprehensively searched four databases (Embase, PsycINFO, MEDLINE and CENTRAL) in addition to grey literature. Studies necessarily consisted of at least one patient who received both rTMS and tDCS for a psychiatric condition or symptom. Multiple validated tools were used for appraisal of quality and risk of bias.
Results: Fourteen studies were reviewed, which related to unipolar depression (five), bipolar disorder (two), obsessive-compulsive disorder (two), chronic insomnia (two), Alzheimer’s Disease (one), stress (one) and depressive and anxiety symptoms (one). Three Randomized controlled trials (RCTs) on unipolar depression generally showcased superior depressive symptom improvement, response and remission rates compared to rTMS or tDCS alone. One RCT on chronic insomnia noted greater improvements in sleep quality/efficiency and depressive symptoms compared to monotherapy. The frequency of side effects with combined treatment was comparable to monotherapy. The reviewed studies noted no significant adverse events.
Conclusion: The current body of evidence highlights a likely superior efficacy of combining rTMS and tDCS for unipolar depression compared to either modality alone. Future studies can extend combined treatment to other psychiatric conditions using protocols that have shown previous success in monotherapy studies.
