Authors: Frye MA, et al.
Title: A placebo-controlled study of lamotrigine and gabapentin monotherapy in refractory mood disorders.
Reference: J Clin Psychopharmacol 2000;20:607-14.
Purpose: To evaluate the efficacy of lamotrigine and gabapentin monotherapy versus placebo in refractory bipolar and unipolar mood disorders.
Study design: Randomized, double-blinded, cross-over trial. 
Follow up: Three 6-week monotherapy evaluations.
Patients: 31 refractory unipolar and bipolar patients.
Treatment: Lamotrigine tapered to a maximum of 500 mg/day, gabapentin titrated to a maximum of 4,800 mg/day, as tolerated.
Results: Response rates of patients were 52% for lamotrigine, 26% for gabapentin, and 23% for placebo. Lamotrigine-treated patients showed a significant response compared with placebo, whereas gapabentin-treated patients did not. Weight change was  -0.96 kg for lamotrigine,  +1.83 kg for gabapentin and -0.40 for placebo.