The 'disconnect' between initial judgments of lamotrigine vs. its real-world effectiveness in managing bipolar disorder. A tale with wider ramifications

Abstract

Objective: To detail the disconnect between the quantified efficacy of the mood stabilizer lamotrigine in its registration controlled trials and its later judged clinical effectiveness and consider some determinants of disconnects between some efficacy trial findings and 'real-world' clinical effectiveness judgments.

Method: Published articles considering lamotrigine as a treatment for the bipolar I or II disorders were selected for review. While randomized controlled trials were weighted, we also consider open trials and effectiveness observations from clinician researchers and demonstrate that lamotrigine has been quite variably judged over time.

Results: We suggest that the early trials evaluating lamotrigine for acute bipolar disorder depression focused on a suboptimal clinical target, and in so doing, ensured less lamotrigine efficacy compared with trials of bipolar disorder preventative treatment. Moreover, a number of additional methodological limitations compromised analyses. We also detail variable reporting of actual study results. The initial sharp disconnect (between efficacy and effectiveness judgments) has narrowed as lamotrigine has been evaluated and progressively taken up as a maintenance mood stabilizer.

Conclusion: The lamotrigine disconnect story provides a number of salutary lessons that are salient to evaluating the effectiveness and ecological niche of any psychotropic medication. The lamotrigine story presented here argues strongly for the wisdom of encouraging an iterative process between efficacy studies and clinical observation.

Keywords: bipolar disorder; depression; lamotrigine; randomized controlled trial; review.