ABSTRACT
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.
Subject(s)
Antimanic Agents/pharmacology , Bipolar Disorder/drug therapy , Cerebral Cortex/drug effects , Facial Expression , Triazines/pharmacology , Adolescent , Adult , Affect , Antimanic Agents/therapeutic use , Bipolar Disorder/physiopathology , Bipolar Disorder/psychology , Brain Mapping/methods , Cerebral Cortex/physiopathology , Female , Humans , Image Processing, Computer-Assisted/methods , Lamotrigine , Magnetic Resonance Imaging , Male , Middle Aged , Neural Pathways/drug effects , Neural Pathways/physiopathology , Pattern Recognition, Visual , Pilot Projects , Recognition, Psychology , Triazines/therapeutic useABSTRACT
Verbal working memory and emotional self-regulation are impaired in Bipolar Disorder (BD). Our aim was to investigate the effect of Lamotrigine (LTG), which is effective in the clinical management of BD, on the neural circuits subserving working memory and emotional processing. Functional Magnetic Resonance Imaging data from 12 stable BD patients was used to detect LTG-induced changes as the differences in brain activity between drug-free and post-LTG monotherapy conditions during a verbal working memory (N-back sequential letter task) and an angry facial affect recognition task. For both tasks, LGT monotherapy compared to baseline was associated with increased activation mostly within the prefrontal cortex and cingulate gyrus, in regions normally engaged in verbal working memory and emotional processing. Therefore, LTG monotherapy in BD patients may enhance cortical function within neural circuits involved in memory and emotional self-regulation.
