A Study of the Effectiveness and Safety of Topiramate in the Treatment of Patients With Bipolar Disorder

Inclusion Criteria: * Diagnosis of Bipolar I Disorder by criteria of Diagnostic and Statistical Manual of Mental Diseases, 4th edition (DSM-IV), and currently experiencing a manic or mixed episode by DSM-IV and Structured Clinical Interview criteria * experienced at least one previous manic or mixed episode * Young Mania Rating Scale (YMSR) score \>=20 * physically healthy * females must be postmenopausal, surgically sterile, or using adequate contraceptive measures, and have a negative pregnancy test. Exclusion Criteria: * Diagnosis of alcohol or substance dependence (with the exception of nicotine or caffeine dependence) by DSM-IV criteria * DSM-IV Axis I diagnosis of schizoaffective disorder or impulse control disorder * experienced a manic episode while taking an antidepressant or psychostimulant drug * no significant and untreated or unstable medical illness of the liver, kidney, heart, lungs, or endocrine system * no hypersensitivity to topiramate or have previously participated in a topiramate study.