Impact of GABA-Enhancing Agents on Cortical GABA Concentrations Across the Menstrual Cycle in Women

Inclusion criteria

• Women ages 18-45 and able to give voluntary written informed consent;
• Regular menstrual periods of 24-35 days in length;
• Body mass index 18.5 to 30 kg/m2;
• No past or present DSM-IV psychiatric or substance dependence diagnosis by structured diagnostic interview (SCID-NP); no substance abuse history within the previous 2 years;
• Absence of mood symptoms across the menstrual cycle during one month of prospective daily ratings with the Daily Record of Severity of Problems (DRSP); the DRSP is based on the DSM-IV research criteria for premenstrual dysphoric disorder (PMDD) and has been used in numerous studies to confirm the presence or absence of significant premenstrual mood and behavioral difficulties;
• Must be willing and able to participate in at least three of the four challenge paradigms.

Exclusion criteria

• Medical, neurologic or cerebrovascular disorder (CVA, seizure disorder, etc.);
• Family history of first degree relative with an Axis I psychiatric or substance dependence disorder (excepting alcohol and nicotine) (per subject report);
• Current treatment with psychoactive medication;
• Diabetes controlled by means other than diet;
• Use of steroid contraceptives (any method involving hormones) within the previous 4 months;
• Habitual consumption of more than 7 alcoholic drinks per week or more than 2 drinks on any particular occasion; must be willing to abstain from alcohol consumption for 48 hours prior to each 1H-MRS scan;
• Implanted metallic devices.