Effects of Noninvasive Brain Stimulation Techniques on BDNF Levels

Effects of Noninvasive Brain Stimulation Techniques on BDNF Levels

The aim of this study is to investigate the effects of non invasive brain stimulation - NIBS - techniques (Electroconvulsivotherapy - ECT, transcranial Direct Current Stimulation - tDCS, repetitive transcranial magnetic stimulation - rTMS) on serum Brain Derived Neurotrophic factor (BDNF) levels in patients with depression and schizophrenia. Four blood samples will be collected in each participants, one before the NIBS sessions, and 3 after the completion of NIBS protocols: one immediately after the end of the NIBS sessions, a second one week after and a last one month after. Two blood samples separated by one month will also be collected in a a group of healthy volunteers.

The hypothesis is that NIBS will modulate BDNF levels and that the modification in serum BDNF levels will be correlated with clinical improvements in the sample of patients.

Inclusion Criteria:

• in the depression group: DSM IV criteria of MDD; HDRS17> 22; stage 2 of resistance; received rTMS or ECT
• in the schizophrenia group DSM IV criteria of schizophrenia; pharmaco-resistance of symptoms (either negative symptoms or auditory verbal hallucination); received rTMS or tDCS
• in the healthy volunteers group : to not have axis I of DSM IV diagnosis; no siblings with axis I DSM IV diagnosis

Exclusion Criteria:

• less than 18 years old
• pregnancy
• received benzodiazepine

In the depression and schizophrenia group:

• bipolar disorder
• other axis I of DSM IV diagnosis (excluding for Tobacco use disorder)