Pilot investigation of the changes in cortical activation during facial affect recognition with lamotrigine monotherapy in bipolar disorder

Background Bipolar disorder is associated with dysfunction in prefrontal and limbic areas implicated in emotional processing. Aims To explore whether lamotrigine monotherapy may exert its action by improving the function of the neural network involved in emotional processing. Method We used functional magnetic resonance imaging to examine changes in brain activation during a sad facial affect recognition task in 12 stable patients with bipolar disorder when medication-free compared with healthy controls and after 12 weeks of lamotrigine monotherapy. Results At baseline, compared with controls, patients with bipolar disorder showed overactivity in temporal regions and underactivity in the dorsal medial and right ventrolateral prefrontal cortex, and the dorsal cingulate gyrus. Following lamotrigine monotherapy, patients demonstrated reduced temporal and increased prefrontal activation. Conclusions This preliminary evidence suggests that lamotrigine may enhance the function of the neural circuitry involved in affect recognition. Declaration of interest The study was funded by an unrestricted educational grant from GlaxoSmithkline.