Preliminary Study to Investigate the Effect of rTMS and SSRI Antidepressants on Leukocyte Expression of the C-FOS and DUSP1 Genes in Patients Treated for Depression (TMSFOS)

Low frequency rTMS (repetitive Transcranial Magnetic Stimulation) for the treatment of patients with depression, is responsible for a decrease in the expression of the C-FOS and DUSP1 genes in peripheral blood leukocytes. The decrease in C-FOS expression could be explained by the inhibiting effect of low-frequency rTMS (in contrast, high-frequency rTMS causes activation of the cerebral cortex) [Rossi, 2009]. This genetic effect could correlate with the antidepressant effect [Hausmann, 2000].

According to this hypothesis, the genetic effect related to medical antidepressant treatments deserves to be studied because we could observe:

- either a decrease in the expression of the C-FOS and DUSP1 genes related to the antidepressant effect of the medical antidepressant treatment,
- or an increase in the expression of the C-FOS and DUSP1 genes related to cerebral activation due to the medical antidepressant treatment.

In summary, we wish to determine the validity of this hypothesis by comparing the genetic effect of rTMS with that of medical antidepressants to know if:

- this genetic effect is specific to rTMS or common rTMS and medical antidepressants
- this effect correlates with the clinical improvement induced by rTMS and by medical antidepressants
- this early modification in the C-FOS and DUSP1 genes may be predictor of the therapeutic response to rTMS and antidepressants (early decrease in gene expression)
- the absence of any decrease or increase in C-FOS and /or DUSP1 expression is a predictor of therapeutic resistance to rTMS and/or medical antidepressants.