Treatment of depression with low-strength transcranial pulsed electromagnetic fields: A mechanistic point of view

• Weak transcranial pulsed electromagnetic fields have an antidepressant effect
• tPEMF influence different neurobiological mechanisms affected in MDD
• Mode of action does possibly involve restoration of disrupted brain connectivity.

BackgroundMood disorders constitute a high burden for both patients and society. Notwithstanding the large arsenal of available treatment options, a considerable group of patients does not remit on current antidepressant treatment. There is an urgent need to develop alternative treatment strategies. Recently, low-strength transcranial pulsed electromagnetic field (tPEMF) stimulation has been purported as a promising strategy for such treatment-resistant depression (TRD). The mode of action of this new technique is however largely unknown.MethodsWe searched PubMed for literature reports on the effects of tPEMF and for information regarding its working mechanism and biological substrate.ResultsMost studies more or less connect with the major hypotheses of depression and concern the effects of tPEMF on brain metabolism, neuronal connectivity, brain plasticity, and the immune system. Relatively few studies paid attention to the possible chronobiologic effects of electromagnetic fields.LimitationsWe reviewed the literature of a new and still developing field. Some of the reports involved translational studies, which inevitably limits the reach of the conclusions.ConclusionWeak magnetic fields influence divergent neurobiological processes. The antidepressant effect of tPEMF may be specifically attributable to its effects on local brain activity and connectivity.