This is multi-center, prospective, observational stud. This study is designed to evaluate the rate of non-serious rash in Korean bipolar I patients.

Inclusion criteria:

• A subject will be eligible for inclusion in this study only if all of the following criteria apply:
• Provides written informed consent
• Male or female age 18 years or older A female subject is eligible to enter and participate in the study if she is of;
• Non-childbearing potential
• Childbearing potential, has a negative pregnancy test at screen
• Diagnosis of bipolar I disorder using DSM-IV criteria

Exclusion criteria:

• A subject will not be eligible for inclusion in this study if any of the following criteria apply:
• Previous or current treatment with lamotrigine
• Presence of a clinically significant psychiatric or physiologic comorbidity, including significant substance abuse, severe depression or mania which is of an unstable or progressive nature that could, in the opinion of the investigator, interfere with participation in this study
• Presence of untreated thyroid disease
• Have active suicidality or homicidality, history of recent suicide attempts within the past year, or, in the investigator's opinion, a marked risk for suicide
• History of severe hepatic or renal insufficiency or significant hematologic disease or other significant medical or psychiatric condition that would interfere with subjects' participation in the study
• Currently participating in another clinical trial, or plans to enroll in another trial while participating in this study
• Currently pregnant or is breastfeeding

Patient setting and reflecting usual clinical practice in general hospital