The Role of Neuromodulators and Deep Brain Stimulation (DBS) in the Treatment of Refractory Bipolar Disorder

Introduction: Refractory bipolar disorder is a complex psychiatric condition characterized by persistent manic and depressive episodes that do not respond adequately to conventional treatments, such as mood-stabilizing medications and antidepressants. This condition results in severe functional impairment, with a significant impact on patients' quality of life. Objective: To evaluate the role of neuromodulators and deep brain stimulation in the treatment of refractory bipolar disorder, analyzing their efficacy, mechanisms of action, and safety based on recent studies. Methodology: The research followed the PRISMA checklist guidelines for systematic reviews. Searches were performed in the PubMed, Scielo, and Web of Science databases, using the descriptors "refractory bipolar disorder", "deep brain stimulation", "neuromodulators", "treatment", and "therapeutic effects". The selection of articles was restricted to the last ten years. Inclusion criteria were: clinical studies on the use of DBS in refractory bipolar disorder, research investigating neuromodulators as additional therapies, and articles published in English, Portuguese or Spanish. Studies with small sample sizes, non-systematic reviews and articles that did not present relevant data on the therapeutic effects of these interventions were excluded. Results: The results indicated that both DBS and neuromodulators have shown to be promising therapies in the treatment of refractory bipolar disorder. DBS, especially when targeting the nucleus accumbens and other areas involved in emotional regulation, has been shown to reduce symptoms of mania and depression in several clinical studies. Neuromodulators, such as those affecting the dopaminergic and serotonergic systems, have also shown efficacy in some patients, but with less consistent results. Conclusion: Both deep brain stimulation and neuromodulators have shown potential in the treatment of refractory bipolar disorder, showing improvements in symptom control in patients resistant to conventional treatments. However, more long-term clinical studies are needed to consolidate the evidence of their efficacy and safety, in addition to optimizing treatment protocols.