Study of Neural Responses Induced by Antidepressant Effects

Over the past decade, neuroimaging tools have rapidly advanced the field of neural biomarkers
of treatment response in depression. Still, despite obvious scientific progress in this
field, the ability to implement neuroimaging biomarkers of antidepressant treatment response
in clinical trial settings is lacking. In order to objectively asses the neural bases of
treatment response in depression, the investigators will use a "Real-time Neurofeedback fMRI
task", specifically designed to record and modulate mood improvement by providing
neurofeedback in the context of the administration of an antidepressant treatment. In a pilot
study, positive neurofeedback during the administration of the drug was associated with
significant acute mood improvement and increased blood oxygen level dependent (BOLD)
responses in the rostral anterior cingulate cortex (rACC), a common neural target of
antidepressant treatments. The central hypothesis is that antidepressant effects in
depression are mediated by increased neural activity in the rACC (AIM1), which can be used in
clinical trials of antidepressant treatment to predict antidepressant effects (AIM 2) and
assess the effect of antidepressant treatment on antidepressant-induced rACC neural responses
(AIM 3). The results obtained from this project are expected to have an important impact on
our ability to understand the cognitive and neural mechanisms implicated in antidepressant
treatment responses in patients with depression, as well as on the ability to implement
neuroimaging biomarkers of treatment response in the clinical trial settings.

Inclusion Criteria:

- A man or woman age of 18 or older.

- Currently experiencing a depressive episode as part of Major Depressive Disorder.

- Able to tolerate lying still on your back for 60 minutes at a time.

- Have had no more than one failed antidepressant trial of adequate dose and duration.

- Have been antidepressant medication-free for at least 21 days prior to collection of
imaging data (5 weeks for fluoxetine)

Exclusion Criteria:

- Are currently taking any psychiatric medication, or any potentially augmenting or
sedative drugs.

- Have a history of inadequate response/tolerability to escitalopram; or history of
resistant depression

- Pregnant or breastfeeding or plan to become pregnant over the duration of the study.

- Have a history (lifetime) of psychotic depressive, schizophrenic, bipolar,
schizoaffective, or other Axis I psychotic disorders.

- Meet criteria for substance dependence in the last 6 months, except nicotine, or
substance abuse in the last 2 months.

- Have a medical condition that contradicts treatment with escitalopram.

- Are currently receiving psychotherapy or any other treatment for your depression.