The purpose of this study is to determine the safety and effectiveness of Depakote ER (Divalproex Sodium Extended-Release Tablets) compared to placebo in the treatment of bipolar disorder, manic or mixed type in children and adolescents ages 10-17 years.

INCLUSION CRITERIA

• Current primary diagnosis of bipolar I disorder, mania or mixed type
• Outpatient between 10 and 17 years of age
• Young Mania Rating Scale score greater than or equal to 20 during screening/washout and at Day 1

EXCLUSION CRITERIA

• Axis I other than Attention Deficit Hyperactivity Disorder (ADHD), Obsessive Compulsive Disorder (OCD), Oppositional Defiant Disorder (ODD), Conduct Disorder (CD), Panic Disorder; or Axis II (e.g., personality disorder) that would interfere with compliance or confound interpretation of study results
• Current manic episode is drug-induced or secondary to a medical disorder (e.g., anti-depressants, hyperthyroidism)
• Expected to require hospitalization for the current manic episode
• Participation in psychotherapy that was started within the past 3 months, or if any significant changes are anticipated
• Has taken atomoxetine or has taken allowed stimulant medication that has not been stable for at least 3 months prior to Day 1, or a dosage adjustment is expected during the study, or that may worsen mood symptoms
• Unable to swallow tablets
• Has received depot psychoactive medication within one inter-injection interval of Day 1
• Urine toxicology screen is positive for phencyclidine (PCP), opiates, cocaine, barbiturates, benzodiazepines or amphetamines
• History of alcohol or substance dependence within past 3 mos. or substance abuse within past month
• History of failed treatment on adequate Depakote (DR or ER) for a manic episode within past 12 months
• Has taken Depakote (DR or ER) regularly for the current manic episode
• Has serious violent, homicidal, or suicidal ideation