Study Overview: This research explores how a hormone called estradiol (E2) affects PTSD (Post-Traumatic Stress Disorder) symptoms in women. PTSD can happen after scary events. The study uses special brain scans called fMRI (functional magnetic resonance imaging) to check stress levels in the brain. Women in three groups are studied: those with PTSD, those who've faced trauma but don't have PTSD, and those without trauma or mental issues.

How It Works: Participants will track their menstrual cycle using the "Clue" app and wear hormone patches before their MRI scans. This helps scientists see if low E2 levels make stress worse. The study also tests if adding more E2 helps reduce PTSD symptoms.

• Study Duration: Involves tracking menstrual cycle and attending two MRI visits.
• Participant Requirements: Must be an African American woman, have a smartphone, and not use hormonal birth control.
• Risks: Must not have certain medical conditions like heart issues or metal implants.

This study hopes to improve treatments for women dealing with PTSD after trauma. It is conducted at Grady Memorial Hospital, Atlanta, Georgia. Participants will contribute to important research about women's mental health.