This is a phase II, open-label clinical trial. This clinical trial has as primary objective to evaluate changes in EEG of a Trigeminal Nerve Stimulation (TNS) treatment protocol for elderly patients with moderate / severe depressive episode.

Inclusion Criteria:

1. patients between 65 and 99 years
2. patients with a diagnosis of depression according to the SCID
3. score greater than or equal to 18 on the Hamilton Rating Scale 17-item version (equivalent to moderate or severe depressive episode)
4. agreement to participate in the study as recommended in the IC.

Exclusion Criteria:

1. patients with psychiatric indication for hospitalization
2. patients with psychiatric comorbidity
3. patients with a diagnosis of personality disorder
4. presence of severe neurological or medical diseases such as neoplasms in activity, neurodegenerative diseases and chronic diseases uncompensated.