Adding Anticonvulsant to Antipsychotic May Benefit Bipolar Patients

Combining lamotrigine (Lamictal) with quetiapine (Seroquel) may improve depressive symptoms and clinical remission rates in patients with bipolar disorder.

A recent study sought to determine whether combination therapy involving quetiapine and lamotrigine can lead to greater improvement in depressive symptoms over a 12-week period compared with quetiapine alone plus a lamotrigine placebo and to folic acid or placebo.

A total of 202 patients aged 16 years or older who required new treatment for depression were recruited from 27 sites between October 21, 2008, and April 27, 2012. Half of the patients were randomly assigned to lamotrigine, and the other 101 patients were assigned to placebo. The patients were also randomly assigned to folic acid or placebo.

After 12 weeks, as well as after 52 weeks, those who received lamotrigine had improved scores on the self-reported Quick Inventory of Depressive Symptomatology test, more so than the patients who received placebo.

“Adding lamotrigine to quetiapine may be an effective and well-tolerated option for many patients with bipolar depression,” the researchers concluded.

They also determined that folic acid was not superior to placebo, and it even reduced the effectiveness of lamotrigine at 12 weeks, which is one counseling point worth mentioning to patients on lamotrigine.

“The interaction between folic acid and lamotrigine was unexpected and additional research is required to investigate this further,” the researchers stated. “…Whatever the cause, the interaction is potentially clinically important because folic acid supplementation might be more likely in some patient groups taking lamotrigine—for example, pregnant women—and as an adjunctive therapy in mood disorder.”

In an accompanying editorial, Gin S. Malhi, MD, of the University of Sydney, wrote that the study could have been constrained by relying on self-reported measures for key outcomes. However, Dr. Malhi argued that self-reported measures to assess outcomes is increasingly common and important for future studies.

The current study findings were published in The Lancet Psychiatry.