Double-blind, Placebo-Controlled Divalproex Sodium ER in Bipolar I or Bipolar II Depression

Inclusion Criteria: * Subject must give consent to participate in the study and sign and date the IRB approved written informed consent form prior to the initiation of any study procedures * Subject must be between the ages of 18 and 70 * Subject must have a diagnosis of bipolar I or II. * Subject must be currently depressed as confirmed by the Mini-International Neuropsychiatric Interview (MINI) * Subject must have a baseline Montgomery-Asberg Depression Scale (MADRS) score of \>19 and Young Mania Rating Scale (YMRS) score of \<12 * Women of childbearing potential must be nonpregnant/nonlactating and using adequate contraception if sexually active * Subject must not be using any concomitant psychotropic medications during the acute phase except prn benzodiazepines Exclusion Criteria: * Subjects lacks the capacity to provide informed consent * Subject has currently or previously used divalproex or Dvpx-ER * Subject is a serious suicide risk or has medically unstable conditions as judged by the investigators * Subject has any alcohol, cocaine, or cannabis dependence within 3 months of study entry * Subject has any cocaine, hallucinogens, opiates, crystal methamphetamine, or MMDA abuse within 3 months of study entry