This is an ancillary study to a clinical trial that is being conducted at Massachusetts
General Hospital. Investigators at MGH are conducting a clinical trial to test the efficacy
of ziprasidone together with escitalopram for treatment-resistant depression (NCT00633399).
This observational study will involve magnetic resonance scans to examine brain chemistry
(neurotransmitter levels), brain activity, and functional connections between brain regions
before and after participating in the trial. The neurotransmitters of interest are glutamate,
glutamine, and GABA. Comparisons will be made between individuals who receive ziprasidone and
individuals who receive an inactive placebo. Differences between participants who respond to
standard antidepressants and those who require additional medication will also be examined.
All participants will have a baseline magnetic resonance scan before starting medication. The
second scan will be after 8 weeks of escitalopram treatment for those who respond or
following 8 weeks of escitalopram plus ziaprasidone or placebo (16 weeks after starting) for
those who do not respond to escitalopram alone. Participants will complete standard rating
scales for depression at each visit.