Hypomania Induced by Adjunctive Lamotrigine

Ms. A was a 23-year-old woman with a DSM-IV diagnosis of major depression and no personal history of bipolar illness and no family history of mood disorders. She had a partial response to 6 months of combination cognitive therapy and buproprion, 300 mg/day. The buproprion was increased to 400 mg/day for 3 months without further improvement. Lamotrigine was then added. After 1 week of 25 mg at bedtime, Ms. A reported an improved mood. After another week at 50 mg/day, she noted a further improved mood, decreased anxiety, and increased energy. Two weeks later, her lamotrigine dose was increased to 75 mg/day. One week thereafter, she reported decreased sleep (2–4 hours per night), increased energy, distractibility, mood lability, and increased spending. She reported no grandiose or other delusions but scored 9 on the Altman Self-Rating Mania Scale (6) (a score >6 suggests hypomania or mania), and she met DSM-IV criteria for hypomania. Her lamotrigine dose was reduced to 50 mg at bedtime. Two weeks later, the hypomanic symptoms subsided (Altman Self-Rating Mania Scale score=5). Fourteen months later, Ms. A remained euthymic.