Researchers (not paid by the drug com- pany) examined data from GlaxoSmithKline’s database of clinical trials for lamotrigine (Lamictal) as a treatment for bipolar depression. Based on five placebo-controlled studies with a combined 1072 participants, Lamictal was found to outperform placebo by a statistically significant extent on some measures. Response rates on the Hamilton Depression Rating Scale (HAM-D) and Montgomery Asberg Depression Rating Scale (MADRS) favored Lamictal over placebo. Remission rates favored Lamictal on the MADRS but not the HAM-D.

Differences in response rates were small; using the Number Needed to Treat as a measurement of efficacy, we need to treat either 11 or 13 additional patients (depending on the method of assessment) in order to produce one treatment response more than placebo. Overall, Lamictal out- performed placebo in patients with severe depressive symptoms, but was not better than placebo for mild to moderate bipolar depression. This may have been due to the fact that there is less of a placebo response in severe depression (Geddes JR, 2009 Br J Psychiatry 2009;194:4-9).

TCPR’s Take: The data present a mixed picture. On some measures, the drug was effective. However, other measures found no advantage for Lamictal over placebo, and all benefits of the drug were quite modest. This meta-analysis confirms the prevailing wisdom that Lamictal is not a tremendously effective medication for acute bipolar depression, but may have a place in some severe episodes.