Augmenting pharmacotherapy with neuromodulation techniques for the treatment of bipolar disorder: a focus on the effects of mood stabilizers on cortical excitability

ABSTRACT

Introduction: Mood stabilizers and antipsychotics have been demonstrated to be effective in Bipolar Disorder, with lithium as the gold standard. However, the presence of adverse events and treatment-resistance is still a relevant issue. To this respect, the use of brain stimulation techniques may be considered as an augmentation strategy, with both Transcranial Magnetic Stimulation (TMS) and Transcranial Direct Current Stimulation (tDCS) having shown some level of efficacy in bipolar patients although clinical trials are still not sufficient to draw any conclusion.

Areas covered: The authors have conducted a systematic review of the literature, in order to evaluate the role of mood stabilizers on neural activity and cortical excitability. Furthermore, the article reviews neuromodulation techniques and highlights the potential of integrating pharmacological first-line therapies with these techniques to treat BD patients.

Expert opinion: The combination of neuromodulation techniques and available pharmacotherapies is a valuable opportunity which is not undermined by specific effects on cortical excitability and could improve BD patient outcome. Neurostimulation techniques may be considered safer than antidepressant treatments in BD, with a lower level of manic switches and may represent a new treatment strategy in BD depressive episodes.

KEYWORDS:

• Bipolar disorder
• cortical excitability
• neurostimulation
• augmentation treatment strategies

Article highlights

• Although mood stabilizers and antipsychotics have been shown to be effective in Bipolar Disorder, the presence of adverse events and treatment-resistance is still a relevant issue. The use of brain stimulation techniques may be considered as an augmentation strategy. Indeed, both TMS and tDCS have shown some level of efficacy in bipolar patients.

• Given the efficacy of neuromodulation techniques in MDD, a comparable profile of efficacy could be postulated in Bipolar Depression.

• Motor excitability in BD is moderately influenced by most of the available pharmacotherapies. Lamotrigine and carbamazepine have significant effects on cortical excitability, being able to increase MT, while other drugs like valproate and lithium have shown no significant effects on cortical excitability.

• Neurostimulation techniques may be considered safer than antidepressant treatments in BD and may therefore represent a new treatment strategy in BD depressive episodes.

• The combination of neuromodulation techniques and available pharmacotherapies is not undermined by specific effects on cortical excitability and could improve the outcome in BD.

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Disclosure

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Contents

Tables and figures included in the article are original contents.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Additional information

Funding

This manuscript has not been funded.