Inclusion Criteria:

• Outpatients aged 10-17 years
• Currently meet Diagnostic and Statistical Manual of Mental Disorders IV-Text Revision (DSM-IV-TR) criteria for bipolar disorder, type I, II or Not Otherwise Specified (NOS) as determined by the Schedule for Affective Disorders and Schizophrenia in School-Age Children-Present/Lifetime (Kiddie-SADS-PL)
• Experiencing manic, hypomanic or mixed states as determined by clinical diagnosis and K-YMRS equal to or more than 14
• General good health as determined by medical history, physical examination, and laboratory evaluations
• Female adolescents, if sexually active, must practice birth control methods approved by the primary investigator
• Ability to swallow tablets
• Subject's parent or guardian must be fully capable of monitoring the subject's disease process and compliance to treatment
• Parent(s) or legal guardian(s) must read and sign the informed consent form after the nature of the study has been fully explained and assent must be obtained from subjects.

Exclusion Criteria:

• Have a lifetime DSM-IV-TR Axis I disorder diagnosis of autistic disorder, schizophrenia, schizoaffective disorder, or other psychotic disorders
• DSM-IV-TR diagnosis of alcohol or substance abuse or dependence within the past 6 months
• Serious or unstable medical or neurological conditions which require concomitant medications
• Judged by the PI to be acutely suicidal or homicidal, or at imminent risk of injuring self or others or causing significant damage to property—i.e., subject needs to be in an inpatient facility
• Known or suspected IQ less than 70
• Have a DSM-IV-TR diagnosis of anorexia and/or bulimia at the time of screening or within the last six months
• Female who is pregnant or nursing
• Subjects with a history of syncopal episodes (sudden loss of consciousness with loss of postural tone and not preceded by a pre-syncopal phase) or unexplained loss of consciousness
• Subjects with a history of significant cardiovascular disease or significant concurrent cardiovascular disease, including uncontrolled hypertension, hypotension, congestive heart failure or congenital heart disease
• Subjects with a history of cardiac arrhythmias, conduction abnormalities or known personal history or QT prolongation (including congenital long QT syndrome)
• Subjects with a known genetic risk for QT syndrome determined by family history in first degree relatives
• Subjects taking any medications known to interact with ziprasidone or subjects taking any medications which have been consistently observed to prolong the QT interval
• Subjects with a clinically significant ECG abnormality at screening
• Subjects with persistent QTc (Fridericia) * 460 msec at screening
• Screening laboratory values outside the normal range and judged to be clinically significant by the investigator
• Patients and families that are Spanish speaking only will be excluded from the study as some instruments used in the study have not been validated in Spanish