PEMF (Pulsed Electro Magnetic Fields) therapy has been used to stimulate bone repair in non-union since the 1970s. This is an accepted use, which has been approved by the Food and Drug Administration in the US. The mode of action of PEMF is based on creating small electrical fields in tissue and thereby promoting healing. Besides it has been shown that PEMF enhance regeneration of nerve fibers exposed to a lesion For treatment of depression the PEMF equipment, which are provided by the company Re5 A/S, consists of a 220 V impulse generator that creates electrical impulses and an applicator which consists of an electrical cable connected to a helmet on which there are 7 electrical coils on the inside. In comparison with the rTMS (Transcranial Magnetic Stimulation) equipment, which uses stimuli approaching neuronal firing level, the PEMF fields in human is very much lower.

Applied to cells PEMF have a stimulatory effect on intracellular tyrosine kinase activity, especially the Src family. The Src family upregulate NMDAR (N-methyl-D-aspartate) subtype of glutamate receptor thereby gating the production of NMDAR-dependent synaptic potentiation that are vital for processes that underlie physiological and pathological plasticity in the brain. Dysregulation of fibroblast growth factor receptors in frontal cortical regions of the brain seem to be associated with depression. The fibroblast growth factors are highly dependent on the activity of the Src family.

For treatment of depression the PEMF equipment, which are provided by the company Re5 A/S, consists of a 220 V impulse generator that creates electrical impulses and an applicator which consists of an electrical cable connected to a helmet on which there are 7 electrical coils on the inside. In comparison with the rTMS equipment, which uses stimuli approaching neuronal firing level, the PEMF fields in human are very much lower.

PEMF treatment involves placing the treatment helmet on the head and connecting it to a power source (220 V), which leads to induction of a pulsating magnetic field. The treatment was given for 30 min once or twice daily for 8 weeks. Participants are awake during these treatments and sit in a chair where they can read or eat. Pilot data demonstrates that the treatment can give mild transient nausea. No other side effects have been observed.

Inclusion Criteria:

• Treatment resistant depression is defined as treatment with at least two antidepressants from different classes in an optimal dose and with sufficient duration (at least 8 weeks).
• A score on HamD17 above 17.
• Antidepressant medication must not have been changed 4 weeks before inclusion.

Exclusion Criteria:

A Ham-D17 item 3 at 2 or more (suicidal risk increased) A moderate manic condition (MAS-M above 14) The participant must not be under some sort of restrictions Pregnancy Severe personality disorders Psychotic mental disorders Brain diseases

Publication in Peer-Reviewed Journals Participation in Congresses

Planned to be published in 2018