An open longitudinal study of patients with bipolar rapid cycling treated with lithium or lamotrigine for mood...

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.

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.

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.

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.