Lamotrigine for acute bipolar depression: An exploratory item-level analysis.

The results suggested a significant treatment effect on core symptoms of depression. A floor effect appeared to limit the sensitivity of other scale items. Given the exploratory nature of the analysis, firm conclusions cannot be drawn, although the results were consistent with past research. Relying on total depression scale sum scores over targeted assessments of core depressive symptoms may have impeded signal detection in the original trials.