Lamotrigine in the immediate treatment of outpatients with depersonalization disorder without psychiatric comorbidity: randomized, double-blind, placebo-controlled study.

Objective: Depersonalization disorders (DPDs) are highly prevalent in population. However, the effect of lamotrigine on outpatients with DPD without psychiatric comorbidity has not been studied in a double-blind placebo-controlled design.
Method: Eighty patients (all men) were washed out from all medications. Each patient was randomized either to receive lamotrigine (40 patients) for 12 weeks or matched on placebo (40 patients) in a double-blind manner. Eligible participants, in addition to meeting the criteria for DPD from Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision, were required to be between 18 and 65 years. Response was defined as a 50% reduction in the Cambridge Depersonalization Scale. Response effects with lamotrigine and placebo were compared by using analysis of variance and χ² tests. Six patients did not return for at least 1 subsequent assessment, and 74 patients dropped out (36 taking lamotrigine and 38 taking placebo) in the valuables study group.
Results: Of the 36 lamotrigine-treated participants, 26 responded by 12 weeks versus 6 of the 38 placebo-treated participants (P < 0.001). The most common and problematic adverse effect in the lamotrigine group was rash.
Conclusions: The authors believe this to be the first double-blind placebo-controlled randomization study to test the efficacy of lamotrigine in the management of outpatients with DPDs. These need to be replicated in a larger study group.