The purpose of this study is to find out what parts of the brain have increased or decreased
activity when people are depressed and how antidepressant medicine changes this activity in
depressed patients. The genetic samples collected are to look at variation in a gene
(serotonin transporter gene), which affects the functioning of the chemical serotonin in the
This study will measure the activity in different parts of the brain, while the patients are
seeing some pictures, using Magnetic Resonance Imaging (MRI) scan. For this study three MRI
scans will be conducted. One before the patient begins on any medication, one during the
study after 3 weeks of treatment and one after six more weeks of treatment with a standard
antidepressant called Escitalopram(trade name: Lexapro).
- Ages 18-50 years and able to give voluntary informed consent.
- Satisfy criteria for Major Depressive Disorder (MDD) and current depressed episode
using the Mini International Neuropsychiatric Interview (M.I.N.I.).
- 17-item Hamilton Depression Rating Scale (HDRS) score > 18.
- Satisfy criteria to undergo an MRI scan based on MRI screening questionnaire.
- Able to be managed as outpatients for initial assessment and during treatment as
ascertained by the following -
- Symptoms not worsening by more than 10 points on the HDRS during the course of the
- No danger to self or others.
- Meeting DSM-IV criteria for schizophrenia, schizophreniform disorder, schizoaffective
disorder, bipolar disorder, atypical psychosis, mental retardation, or organic mental
(including organic mood) disorder.
- On monoamine oxidase inhibitors in the past 2 weeks.
- History of narrow angle glaucoma.
- Lack of response of the current episode of depression to two or more adequate courses
of antidepressant therapy at a clinically appropriate dose for a minimum of 4 weeks
or, in the judgment of the investigator, the patient meets criteria for
- Use of neuroleptic in the past 2 weeks.
- Use of antidepressants in the past 2 weeks. If on fluoxetine in the past, then
should not have been on this medication for 4 weeks.
- Use of mood stabilizers in the past 2 weeks.
- Use of benzodiazepines in the past 2 weeks.
- Acutely suicidal or homicidal or requiring inpatient treatment.
- Meeting DSM-IV criteria for other substance dependence within the past year, except
caffeine or nicotine. The criteria will be evaluated by interview and urinary
toxicology screening initially and on test days.
- Use of alcohol in the past 1 week.
- No serious medical or neurological illness as assessed by physical examination and
laboratory examination including CBC and blood chemistry.
- Current pregnancy or breast-feeding.
- Metallic implants.
- Previously known positive HIV blood test as reported by the subject.