RESUMEN
Recent research has provided novel insights into the major depressive disorder (MDD) and identified certain biomarkers of this disease. There are four main mechanisms playing a key role in the related pathophysiology, namely (1) monoamine systems dysfunction, (2) stress response, (3) neuroinflammation, and (4) neurotrophic factors alteration. Robust evidence on the decreased homovanillic acid in the cerebrospinal fluid (CSF) of patients with MDD supports a rationale for therapeutic stimulation of the medial forebrain bundle activating the dopamine reward system. Both activation and suppression of the hypothalamic-pituitary-adrenal (HPA) axis in MDD and related conditions indicate usefulness of its evaluation for the disease subtyping. Elevated proinflammatory cytokines (specifically, interleukin-6) in CSF imply the role of neuroinflammation resulting in activation of the tryptophan-kynurenine pathway. Finally, neuroplasticity and trophic effects of the brain-derived neurotrophic factor (BDNF) may be related to both structural abnormalities of the brain in MDD and the underlying mechanisms of various therapies. In addition, the gut-brain interaction is pivotal, since lack of beneficial microbes confer the risk of MDD through negative effects on the dopamine system, HPA axis, and vagal nerve. All these factors may be highly relevant to treatment of MDD with contemporary brain stimulation therapies.
Asunto(s)
Trastorno Depresivo Mayor , Sistema Hipotálamo-Hipofisario , Encéfalo , Trastorno Depresivo Mayor/tratamiento farmacológico , Dopamina/metabolismo , Humanos , Sistema Hipófiso-SuprarrenalRESUMEN
Transcranial magnetic stimulation (TMS) has been widely applied for evaluation of the cortical eloquence through creation of the temporary "virtual lesion" allowing assessment of the evaluated function within the targeted region, which may be also employed for management of mental symptoms or modification of the abnormal behavior. It is believed that this non-invasive neuromodulation modality has a double impact on neurons-primary modulation of electrical activity and stimulation of neuroplasticity; the latter can be facilitated by repeated administration of TMS during multiple sessions over sufficiently long periods of time to induce consolidation of treatment effects through their recall at psychological, physiological, and cellular levels. These principles were employed in our data-driven, tailored strategy based on the modifications of TMS protocol and its adaptation to newly appearing changes of the clinical situation along with administration of prolonged and/or repeated courses of therapeutic stimulation, which showed high efficacy resulting in complete relief of depressive symptoms or substance use in 75% of treated patients at 1-year follow-up. Such results justify application of repetitive TMS for management of psychiatric disorders and warrant additional evaluation of its efficacy in further clinical studies.
Asunto(s)
Conducta Adictiva , Trastornos Relacionados con Sustancias , Depresión , Humanos , Trastornos Relacionados con Sustancias/etiología , Estimulación Magnética Transcraneal/métodosRESUMEN
Among few available therapeutic options for patients with treatment-resistant depression, chronic stimulation of the vagus nerve using an implanted stimulator, the so-called vagal nerve stimulation (VNS), has been shown to be both effective and safe technique, based on the multitude of studies. While the exact degree of its efficacy remains a subject of discussion, the strong scientific basis and a large body of data from completed and ongoing clinical trials suggest that VNS remains a viable option for those patients, who have exhausted less invasive treatment approaches.