Patient description: The patient is a 15 year old girl with the history of recurrent bilateral headache. The attacks come 2 times or more per week and each episode lasts around a day or a half. The pain is pulsating in quality and severe in intensity, causing trouble in her routine physical activity. The attacks are associated with nausea and photophobia. She recently noticed that that there are more attacks around her menstrual period. She is diagnosed with the migraine headache and is under treatment. She is a high-school student and living with her both parents. She is a book worm and spend her free time in a public library near her home. She is also interested in writing stories and has several short stories in English. She rarely does exercise. Her BMI is 21 with the BP of 100/60. There is nothing remarkable in her physical exam.

Clinical trial eligibility criteria: eligible ages (years): 12.0-17.0,  Migraine Subject and subject's legal representative have voluntarily signed and dated an IRB-approved informed assent form and an IRB-approved informed consent form, respectively, before any study-specific procedures or tests are performed, including the discontinuation of any prohibited medications Subject is male or a non-pregnant, non-lactating female Subject is between 12 and 17 years of age, inclusive, at randomization Subject weighs between 77 lbs (i.e., 35 kg) and 220 lbs (i.e., 100 kg) inclusive Subject currently has migraine headaches diagnosed according to the International Headache Society (IHS) diagnostic occurring at an average frequency of at least 3, but no more than 12, migraine headaches per month during the 3 months prior to screening. Migraine headaches separated by a headache-free interval of < 48 hours will be considered one migraine headache in assessing this criterion Subject's initial onset of migraine headache precedes the Screening Visit by at least 12 months Subject is judged to be in generally good health based on the results of a medical history, physical examination, 12-lead electrocardiogram (ECG), and laboratory profile. When the Screening and Baseline Visits are combined as described in Section 5.1, continuing participation in the Baseline Phase will be contingent upon laboratory and ECG results. Any repeat laboratory testing must be completed in consultation with the Abbott Medical Monitor prior to randomization. Experimental Phase The following define for subject enrollment in the Experimental Phase and subsequent randomization and study drug assignment Subject experienced at least 3, but no more than 12, migraine headaches (separated by headache-free intervals of at least 48 hours), diagnosed according to the IHS diagnostic criteria,6 during the 4-week Baseline Phase of the study; and Subject is still eligible for the study based on Baseline Phase criteria  Baseline Phase History of allergic reaction or significant sensitivity to valproate or similar drugs History of noncompliance with medication or medical instructions Previously randomized in this study Recent (previous 6 months) history of drug and/or alcohol abuse or has a positive urine drug screen, at the Screening Visit, for drugs of abuse (e.g., amphetamines, barbiturates, benzodiazepines, cocaine, opiates, and phencyclidine [PCP]) Female, of childbearing potential, and not using an effective method of birth control (e.g., total sexual abstinence or contraceptives) History of cluster headaches (see Appendix G, Diagnostic for Headaches), seizure disorder, or suspected history of seizure disorder History of headaches of any type occurring on 15 or more days per month, on average, or uses medications excessively for headaches (e.g., regularly taking medication on more than 10 days per month) Failed more than 2 adequate regimens of prophylactic antimigraine medications, including antiepilepsy drug(s) (e.g., gabapentin, topiramate) or 1 adequate regimen of valproate Use of any prophylactic antimigraine medication within a period equivalent to < 5 half-lives of that medication before entering the Baseline Phase