Vagus nerve stimulation: An update on a novel treatment for treatment-resistant depression.

In this review, we provide an overview of essential clinical trials examining the effect of vagal nerve stimulation (VNS) in treatment-resistant depression (TRD), the applicable neuroanatomy of the vagus nerve, and the proposed mechanism of action (MOA) of VNS in TRD. Vagal nerve stimulation (VNS) is currently the only FDA-approved neurostimulation treatment for severe treatment-resistant depression (TRD). The implanted VNS device sends electrical impulses to the left cervical vagus nerve, resulting in stimulation of afferent vagal brainstem pathways known to be associated with mood regulation. Within the last decade, several clinical trials have attempted to further elucidate this effect specifically in TRD. Early clinical trials including the D01, D02, and D03 trials showed promising evidence of the antidepressant efficacy and durability of VNS as a treatment for TRD. Later trials comparing VNS and treatment-as-usual (TAU) resulted in similar findings regarding antidepressant efficacy and durability. VNS was additionally found to be beneficial in improving quality of life and suicidality among unipolar TRD patients and depression among bipolar TRD patients. Ongoing and future studies such as the RECOVER trial continue to investigate the psychiatric benefits of VNS within the TRD population. Although the MOA of VNS in TRD is still not fully understood, recent brain imaging studies and animal studies have proven instrumental in addressing this knowledge gap.

A phase 2 trial of inhaled nitrous oxide for treatment-resistant major depression.

Nitrous oxide at 50% inhaled concentration has been shown to improve depressive symptoms in patients with treatment-resistant major depression (TRMD). Whether a lower concentration of 25% nitrous oxide provides similar efficacy and persistence of antidepressant effects while reducing the risk of adverse side effects is unknown. In this phase 2 clinical trial (NCT03283670), 24 patients with severe TRMD were randomly assigned in a crossover fashion to three treatments consisting of a single 1-hour inhalation with (i) 50% nitrous oxide, (ii) 25% nitrous oxide, or (iii) placebo (air/oxygen). The primary outcome was the change on the Hamilton Depression Rating Scale (HDRS-21). Whereas nitrous oxide significantly improved depressive symptoms versus placebo (P = 0.01), there was no difference between 25 and 50% nitrous oxide (P = 0.58). The estimated differences between 25% and placebo were -0.75 points on the HDRS-21 at 2 hours (P = 0.73), -1.41 points at 24 hours (P = 0.52), -4.35 points at week 1 (P = 0.05), and -5.19 points at week 2 (P = 0.02), and the estimated differences between 50% and placebo were -0.87 points at 2 hours (P = 0.69), -1.93 points at 24 hours (P = 0.37), -2.44 points at week 1 (P = 0.25), and -7.00 points at week 2 (P = 0.001). Adverse events declined substantially with dose (P < 0.001). These results suggest that 25% nitrous oxide has comparable efficacy to 50% nitrous oxide in improving TRMD but with a markedly lower rate of adverse effects.

EAP 2.0: reimagining the role of the employee assistance program in the new workplace.

Mental illness is a highly prevalent problem that affects millions of individuals. Like many other previous natural disasters and terrorist attacks, the recent Covid-19 pandemic has placed an enormous stress on the world and its workforce. In many ways the pandemic revealed gaps in the quality and availability of mental health resources, and, by magnifying the intense demand, it also spurred innovation. Telemedicine and virtual trauma-related services became examples of ways in which evaluation, treatment and counselling services could be delivered directly and efficiently to people who were confined to their dwellings and hospital beds. For many, the workplace has been a source of stress but also a vital component of one's self-worth, day-to-day purpose, and a resource for wellness programs and brief counselling services, not to mention, at least in many countries like the United States, a source for health insurance. The employee assistance program (EAP) is an example of a workplace-counselling and triage service that has enormous potential to meet the growing needs of individuals both in 'normal' times and during disasters. By better understanding the EAP's current structure alongside the advent of new technologies, it may be possible to develop a new and improved EAP model to meet a changing global landscape. For EAP to succeed and ultimately be scalable in an increasingly competitive and value-conscious marketplace, its processes of care will first require a bottom-up review with meaningful outcomes data. This will be necessary to drive continuous quality improvement and to demonstrate EAP 2.0's value to both employer and employee alike.

Extreme Overvalued Beliefs.

An extreme overvalued belief is shared by others in a person's cultural, religious, or subcultural group. The belief is often relished, amplified, and defended by the possessor of the belief and should be differentiated from a delusion or obsession. Over time, the belief grows more dominant, more refined, and more resistant to challenge. The individual has an intense emotional commitment to the belief and may carry out violent behavior in its service. Study participants (n = 109 forensic psychiatrists) were asked to select among three definitions (i.e., obsession, delusion, and extreme overvalued belief) as the motive for the criminal behavior seen in 12 randomized fictional vignettes. Strong interrater agreement (kappa = 0.91 [95% CI 0.83-0.98]) was seen for vignettes representing extreme overvalued belief. Vignettes representing delusion and obsession also had strong reliability (kappa = 0.99 for delusion and 0.98 for obsession). This preliminary report suggests that forensic psychiatrists, given proper definitions, possess a substantial ability to identify delusion, obsession, and extreme overvalued belief. The rich historical foundation of extreme overvalued belief and this small survey study highlight the benefit of inclusion of "extreme overvalued belief" in future glossaries of the Diagnostic and Statistical Manual.

Involuntary Psychotropic Treatment in the Correctional System: Revisiting the Legal Standards.

Correctional facilities are obligated to provide psychotropic medications, as part of standard psychiatric care, to inmates with serious mental illness. The right to refuse such medication treatment has become one of the most important and contested areas of legal regulation of correctional mental health. This article will focus on the three cases that have come before the U.S. Supreme Court thus far, as well as their implications for future medicolegal directions in pursuing involuntary treatment.

Neurostimulation Therapies.

Depression is one of the most disabling conditions in the world. In many cases patients continue to suffer with depressive disorders despite a series of adequate trials of medication and psychotherapy. Neuromodulation treatments offer a qualitatively different modality of treatment that can frequently prove efficacious in these treatment-refractory patients. The field of neuromodulation focuses on the use of electrical/electromagnetic energy, both invasively and noninvasively, to interface with and ultimately alter activity within the human brain for therapeutic purposes. These treatments provide another set of options to offer patients when clinically indicated, and knowledge of their safety, risks and benefits, and appropriate clinical application is essential for modern psychiatrists and other mental health professionals. Although neuromodulation techniques hold tremendous promise, only three such treatments are currently approved by the United States Food and Drug Administration (FDA) for the treatment of major depressive disorder: electroconvulsive therapy (ECT), vagus nerve stimulation (VNS), and repetitive transcranial magnetic stimulation (rTMS). Additionally, numerous other neurostimulation modalities (deep brain stimulation [DBS], magnetic seizure therapy [MST], transcranial electric stimulation [tES], and trigeminal nerve stimulation [TNS]), though currently experimental, show considerable therapeutic promise. Researchers are actively looking for ways to optimize outcomes and clinical benefits by making neuromodulation treatments safer, more efficacious, and more durable.

The Mechanism of Action of Vagus Nerve Stimulation in Treatment-Resistant Depression: Current Conceptualizations.

Stimulation of the left cervical vagus nerve, or vagus nerve stimulation (VNS), brings about an antidepressant response in a subset of treatment-resistant depression (TRD) patients. How this occurs is poorly understood; however, knowledge of the neuroanatomic vagal pathways, in conjunction with functional brain imaging studies, suggests several brain regions associated with mood regulation are critical: brainstem nuclei (locus coeruleus, dorsal raphe, and ventral tegmental area), thalamus, and insular and prefrontal cortex. Furthermore, animal studies suggest that VNS enhances neuroplasticity and changes in neuronal firing patterns. Continued study to better understand the mechanism of action of VNS in TRD is warranted.

Chronic Vagus Nerve Stimulation Significantly Improves Quality of Life in Treatment-Resistant Major Depression.

OBJECTIVE: To compare quality-of-life (QOL) change associated with treatment as usual (TAU, any antidepressant treatment) versus adjunctive vagus nerve stimulation treatment (VNS + TAU) in a population of patients with treatment-resistant depression (TRD) for 5 years. METHODS: Self-reported QOL assessments, using the Quality of Life Enjoyment and Satisfaction Questionnaire Short Form (Q-LES-Q-SF), were gathered in a multicenter, longitudinal registry (January 2006-May 2015) comparing the antidepressant efficacy of VNS + TAU versus TAU in TRD. All depressed patients (N = 599), with either unipolar or bipolar depression, met DSM-IV-TR major depressive episode criteria and failed at least 4 adequate antidepressant trials. The Montgomery-Asberg Depression Rating Scale (MADRS) was administered by blinded raters. Q-LES-Q-SF scores in the treatment arms were compared via linear regression; linear regression was employed to compare QOL differences with percent decrease in MADRS. A subanalysis comparing Q-LES-Q-SF functional domain change was performed. RESULTS: 328 VNS + TAU and 271 TAU patients with TRD were compared. On average, VNS + TAU demonstrated a significant, comparative QOL advantage over TAU (as demonstrated via non-overlapping 95% confidence bands) that began at 3 months and was sustained through 5 years and was reinforced using a clinical global improvement measure. Patients receiving VNS + TAU, but not TAU alone, demonstrated a clinically meaningful QOL improvement (34% MADRS decrease) well below the classically defined antidepressant response (50% MADRS decrease). Exploratory post hoc subanalysis demonstrated that VNS + TAU had a significant advantage in multiple Q-LES-Q domains. CONCLUSION: Compared to TAU, adjunctive VNS significantly improved QOL in TRD, and this QOL advantage was sustained. Further, TRD patients treated with VNS experienced clinically meaningful QOL improvements even with depression symptom reduction less than the conventional 50% reduction used to ascribe "response."