Some antiseizure medication levels are affected by hormones. This study is being done to determine if blood levels of lamotrigine or valproate are affected by the hormones in the birth control pill or the menstrual cycle itself.

Participants will be given informed consent and will be asked to have two blood draws at specific times of the menstrual cycle or if on a birth control pill, during the active and inactive pill phases.

Inclusion Criteria:

• Must be a female between 13-45 years of age
• Must have a history of seizures
• Must be taking either lamotrigine (Lamictal) or valproate (Depakote) with or without a birth control pill

Exclusion Criteria:

• Must not be on antidepressant medication, tranquilizers, or other forms of hormonal therapy other than the birth control pill

Two regional epilepsy centers