• add-on therapy;
  • bipolar disorder;
  • clinical benefit;
  • lamotrigine



The objective of the current study was to assess, in a naturalistic treatment setting, the clinical benefits of lamotrigine add-on therapy for patients with bipolar disorder.


This was an open-label, prospective, naturalistic, 12-week, observational study that included 98 bipolar patients treated with lamotrigine add-on therapy, in addition to mood stabilizers or atypical antipsychotics for 1–4 weeks. The clinical benefits of lamotrigine augmentation were evaluated using the Clinical Global Impression-Clinical Benefit (CGI-CB) Scale, and the Clinical Global Impression of Bipolar Disorder-Severity scale was used to evaluate the severity of the patients' conditions.


According to paired t-test analyses, the mean CGI-CB score significantly decreased from 7.2 ± 2.7 at baseline to 3.8 ± 2.5 at Week 12. Likewise, the mean score for Clinical Global Impression of Bipolar Disorder-Severity scale significantly decreased from 4.7 ± 0.9 at baseline to 3.1 ± 1.2 at Week 12. Analysis of covariance showed that the extent to which CGI-CB scores changed from baseline to Week 12 did not significantly differ between patients with bipolar I and II disorder. However, the change in CGI-CB scores between Weeks 4 and 12 was significantly smaller in bipolar II patients than bipolar I patients. A total of 21 (21.4%) patients dropped out during the course of the study, and 30 patients (30.6%) reported 82 adverse events.


The results of this study demonstrated that the use of lamotrigine in patients with bipolar disorder, especially those whom conventional mood stabilizers or antipsychotics are insufficiently effective or intolerable, can be beneficial regardless of the type of bipolar disorder.