Lamotrigine Alone Compared to Lamotrigine Plus Antidepressant for the Treatment of Bipolar II Depression

Lamotrigine will be initiated at 25mg daily for two weeks, then increased to 50mg daily for one week, and then increased to 100 mg daily. The dose may then be adjusted upward or downward by 50-100mg weekly, at the investigator's discretion, provided that it remains within the protocol defined range of 100mg - 400mg daily. For subjects in this combination therapy arm, antidepressant dose will remain constant throughout the study.

Lamotrigine will be initiated at 25mg daily for two weeks, then increased to 50mg daily for one week, and then increased to 100 mg daily. The dose may then be adjusted upward or downward by 50-100mg weekly, at the investigator's discretion, provided that it remains within the protocol defined range of 100mg - 400mg daily. Subjects in this group will discontinue their antidepressants prescribed to them before the study.