Impact of Estrogen on Fear Extinction

The aim of the study was to examine the influence of exogenous estrogen administration on the
activation of the fear extinction network in women. We collected functional MRI data and
psychophysiological indices to test the influence of estrogen on women's ability to regulate
conditioned fear responses. Women underwent a 3day experimental paradigm using classical fear
conditioning. The first day was conducted outside the scanner, while days 2 and 3 were done
inside the fMRI scanner and tested fear extinction learning and recall in days 2 and 3,
respectively. The estrogen (or placebo) pill was given just hours before extinction learning
test on day 2. No followups were conducted after women completed the 3 day study.

Inclusion Criteria:

- Right-handed

- Naturally-cycling (regular cycle)

- No current or past history of Axis I psychiatric disorders

Exclusion Criteria:

- Psychiatric, neurologic or medical condition that would interfere with study
procedures or confound results, ascertained by history.

- History of seizure or significant head trauma (i.e., extended loss of consciousness,
neurological sequelae, or known structural brain lesion).

- History of Axis I psychiatric diagnosis; e.g., history of substance use disorder,
psychotic disorder, bipolar disorder, tic disorder, or eating disorder.

- Use of psychotropic medication within 4 weeks prior to study (within 6 weeks for
fluoxetine, or other long-lived compounds; within one year for neuroleptics).

- Pregnancy (to be ruled out by urine ß-HCG).

- Metallic implants or devices contraindicating magnetic resonance imaging.

- Use of oral contraceptives or non-oral contraceptives containing estrogen and
progesterone within 3 months

- History of breast cancer.

- Allergy to peanut oil.