Transcutaneous Vagal Nerve Stimulation in Trauma Spectrum Psychiatric Disorders

Post-traumatic stress disorder (PTSD) and related trauma spectrum psychiatric disorders, including major depression, borderline personality disorder, and the dissociative disorders, are associated with considerable morbidity and loss of function. Treatment of these disorders, which include medications and psychotherapy, have limitations. New neuromodulation approaches targeting the underlying neurobiology of these disorders—including elevated inflammation, impaired autonomic nervous system activity, and alterations in brain areas that mediate emotion and the stress response—could improve the treatment and management of these patients. Vagal nerve stimulation (VNS) blocks sympathetic and inflammatory responses, and modulates brain areas involved in stress. Implantable VNS devices are approved for treatment refractory depression. New generation transcutaneous VNS devices that stimulate branches of the vagus nerve via the neck (cervical) or ear (auricular) are potentially applicable to trauma spectrum psychiatric disorders. This chapter reviews the effects of VNS on neurobiology and applications to patients with these psychiatric disorders.