This was a 5-year single-site study of bipolar depression utilizing 1H-MR spectroscopy before and after treatment with lamotrigine. At baseline bipolar depressed subjects and age-matched controls underwent a 1H-MRS at Mayo Clinic in Rochester, Minnesota. The bipolar depressed subjects were then be placed on 12-week, open evaluation of lamotrigine monotherapy. After 12 weeks, the bipolar subjects underwent a second 1H-MRS scan.