The primary objective of the study is to evaluate the efficacy of administered maintenance treatments in bipolar disorder I and II, defined as the percentage of patients who experience a relapse episode during the first 9 months after a mood event (manic or depressive).

Inclusion Criteria:

• Subjects who experienced the last acute mood episode during the last 2 months and are in euthymic state (YMRS score ≤12 and HAM-D score ≤12) for at least two weeks
• Diagnosis of bipolar disorder I or II (as per DSM-IV), with or without rapid cycling
• Subjects who have been treated with at least one atypical antipsychotic for the management of an acute mood event (manic or depressive) as monotherapy or in combination with other medication
• Provision of informed consent prior to study participation

Exclusion Criteria:

• Subjects fulfilling criteria for diagnosis of any other psychiatric condition (except from bipolar disorder I or II), as per DSM-IV Axis Ι, concomitant organic mental disorder or mental retardation
• Subjects who have received treatment with a depot
• Substance abuse or dependence (with the exception of nicotine dependence), as defined by DSM-IV criteria
• Inability of subjects to comply with the study protocol.

Outpatients diagnosed with bipolar disorder I or II (as per DSM-IV), who have received therapy with at least one atypical antipsychotic for the acute episode and whose treating physician has considered they have entered the maintenance phase.