The rate of depression patients, who do not react to the treatment despite drugs and psycho-social interventions, is thought to be 15%. The emotional, social and economic hardships still continue in these patients despite the treatment.
In case there is a treatment-resistant depression, the first method to come to mind is Electroconvulsive Therapy (ECT). Nevertheless, it has a limited use due to its side effects. Repetitive Transcranial Magnetic Stimulation, or “rTMS” is an alternative method known to have side effects of minimal level.
Deep TMS (dTMS)
It is implemented as treatment with proven reliability and effect in the case of an rTMS-resistant depression. Deep TMS “(dTMS)”, an advanced version of this one, is a new technology with an approved effectiveness in its use on heavily psychiatric disorders. Its purpose is to accelerate the functioning by creating electrical areas in the deepest brain parts and the ones protected by the upper areas.
Deep TMS (dTMS), as distint from rTMS, can make simultaneously deep interventions to brain parts in different areas. What’s more, it enables the stimulation of the neural networks linking the prefrontal cortex to the limbic system by ensuring the inward distribution of the electrical area created in the upper surface of the brain. These networks are associated with the most primitive, vital mechanisms. By stimulating the reward system and tegmentum area of the brain regarding the reward and motivation it supports the treatment of depression, addiction, schizophrenia and some neurological disorders.
dTMS is reported to have yielded effective results on depression patients who did not get any benefits from ECT. In a study carried out over treatment-resistant patients, it was observed that dTMS administered on the left prefrontal cortex led to sustainable attention and a development in the visual-spatial memory and psychomotor speed.
In a study examining the side effects on depression patients, there were no damages or cognitive impairments found on motor or prefrontal cortices. The same study compared the dTMS implemented at high frequencies to the one superficially implemented at low frequencies and reported that the antidepressant effect of the dTMS implemented at low frequencies was on the decline.
The same study analyzed the difference between dTMS implemented on both areas of the prefrontal cortex and dTMS implemented on solely the left area and found that the dTMS implemented on both sides was less effective. This, in turn, is a finding supporting the hypothesis of the relation between depression and the “asymmetry” forming in the front part of the brain.
When the effects on elder patients were compared, dTMS was found to be more effective than rTMS as it provided a deeper stimulation.