• lamotrigine;
  • lithium;
  • rapid cycling

Objectives: Patients with rapid cycling bipolar disorder are frequently observed to fail conventional treatment. We conducted a preliminary study to explore the potential efficacy of lamotrigine in the treatment of this refractory patient population. Methods: In an open longitudinal investigation, 14 patients with rapid cycling bipolar disorder were treated for 1 year with either lithium or lamotrigine as mood stabilizer. Results: Out of the seven patients with lithium, three out of seven (43%) had less than four and four out of seven (57%) had four or more episodes. In the lamotrigine group, six out of seven (86%) had less than four and one out of seven (14%) had more than four affective episodes (depressive, manic, hypomanic or mixed). In fact, three out of seven (43%) of the patients who were on lamotrigine therapy were without any further affective episodes. There was no evidence of a preferential antidepressant versus antimanic efficacy. Conclusions: Although the study is limited by the small number of patients, the results are in line with other investigations, suggesting efficacy for lamotrigine and a suboptimal response for lithium in rapid cycling bipolar disorder. These preliminary data need to be confirmed with controlled double blind studies.