Pharmacotherapy of anxiety disorders in the 21st century: A call for novel approaches

Neuroproteomics: Unveiling the Molecular Insights of Psychiatric Disorders with a Focus on Anxiety Disorder and Depression

Anxiety and depression are two of the most common mental disorders worldwide, with a lifetime prevalence of up to 30%. These disorders are complex and have a variety of overlapping factors, including genetic, environmental, and behavioral factors. Current pharmacological treatments for anxiety and depression are not perfect. Many patients do not respond to treatment, and those who do often experience side effects. Animal models are crucial for understanding the complex pathophysiology of both disorders. These models have been used to identify potential targets for new treatments, and they have also been used to study the effects of environmental factors on these disorders. Recent proteomic methods and technologies are providing new insights into the molecular mechanisms of anxiety disorder and depression. These methods have been used to identify proteins that are altered in these disorders, and they have also been used to study the effects of pharmacological treatments on protein expression. Together, behavioral and proteomic research will help elucidate the factors involved in anxiety disorder and depression. This knowledge will improve preventive strategies and lead to the development of novel treatments.

Monoamine Oxidase: A Potential Link in Papez Circuit to Generalized Anxiety Disorders

Anxiety is a common mental illness that affects a large number of people around the world, and its treatment is often based on the use of pharmacological substances such as benzodiazepines, serotonin, and 5-hydroxytyrosine (MAO) neurotransmitters. MAO neurotransmitters levels are deciding factors in the biological effects. This review summarizes the current understanding of the MAO system and its role in the modulation of anxiety-related brain circuits and behavior. The MAO-A polymorphisms have been implicated in the susceptibility to generalized anxiety disorder (GAD) in several investigations. The 5-HT system is involved in a wide range of physiological and behavioral processes, involving anxiety, aggressiveness, stress reactions, and other elements of emotional intensity. Among these, 5-HT, NA, and DA are the traditional 5-HT neurons that govern a range of biological activities, including sleep, alertness, eating, thermoregulation, pains, emotion, and memory, as anticipated considering their broad projection distribution in distinct brain locations. The DNMTs (DNA methyltransferase) protein family, which increasingly leads a prominent role in epigenetics, is connected with lower transcriptional activity and activates DNA methylation. In this paper, we provide an overview of the current state of the art in the elucidation of the brain's complex functions in the regulation of anxiety.

Agomelatine for the treatment of generalized anxiety disorder: focus on its distinctive mechanism of action

Generalized anxiety disorder (GAD), the most frequently diagnosed form of anxiety, is usually treated by cognitive-behavioural approaches or medication; in particular, benzodiazepines (acutely) and serotonin or serotonin/noradrenaline reuptake inhibitors (long term). Efficacy, compliance, and acceptability are, however, far from ideal, reinforcing interest in alternative options. Agomelatine, clinically employed in the treatment of major depression, expresses anxiolytic properties in rodents and was effective in the treatment of GAD (including severely ill patients) in several double-blind, short-term (12 weeks) and relapse-prevention (6 months) studies. At active doses, the incidence of adverse effects was no higher than for placebo. Agomelatine possesses a unique binding profile, behaving as a melatonin (MT₁/MT₂) receptor agonist and 5-HT_2C receptor antagonist, yet recognizing neither monoamine transporters nor GABA_A receptors. Extensive evidence supports a role for 5-HT_2C receptors in the induction of anxious states, and their blockade likely plays a primary role in mediating the anxiolytic actions of agomelatine, including populations in the amygdala and bed nucleus of stria terminalis, as well as the hippocampus. Recruitment of MT receptors in the suprachiasmatic nucleus, thalamic reticular nucleus, and hippocampus appears to fulfil a complimentary role. Downstream of 5-HT_2C and MT receptors, modulation of stress-sensitive glutamatergic circuits and altered release of the anxiogenic neuropeptides, corticotrophin-releasing factor, and vasopressin, may be implicated in the actions of agomelatine. To summarize, agomelatine exerts its anxiolytic actions by mechanisms clearly distinct from those of other agents currently employed for the management of GAD.

PLAIN LANGUAGE SUMMARY

How agomelatine helps in the treatment of anxiety disorders.

INTRODUCTION

• Anxiety disorders have a significant negative impact on quality of life.• The most common type of anxiety disorder, called generalized anxiety disorder (GAD), is associated with nervousness and excessive worry.• These symptoms can lead to additional symptoms like tiredness, sleeplessness, irritability, and poor attention.• GAD is generally treated through either cognitive-behavioural therapy or medication. However, widely used drugs like benzodiazepines and serotonin reuptake inhibitors have adverse effects.• Agomelatine, a well-established antidepressant drug, has shown anxiety-lowering ('anxiolytic') properties in rats and has been shown to effectively treat GAD with minimal side effects.• However, exactly how it acts on the brain to manage GAD is not yet clear.• Thus, this review aims to shed light on agomelatine's mechanism of action in treating GAD.

METHODS

• The authors reviewed studies on how agomelatine treats anxiety in animals.• They also looked at clinical studies on the effects of agomelatine in people with GAD.

RESULTS

• The study showed that agomelatine 'blocks' a receptor in nerve cells, which plays a role in causing anxiety, called the 5-HT_2C receptor.• Blocking this receptor, especially in specific brain regions such as nerve cells of the amygdala, bed nucleus of stria terminalis, and hippocampus, produced the anxiety reduction seen during agomelatine treatment.• Agomelatine also activates the melatonin (MT) receptor, which is known to keep anxiety in check, promote sleep, and maintain the sleep cycle.• Agomelatine should thus tackle sleep disturbances commonly seen in patients with GAD.• Beyond 5-HT_2C and MT receptors, signalling molecules in nerve cells that are known to be involved in anxiety disorders (called 'neurotransmitters' and 'neuropeptides') are also affected by agomelatine.

CONCLUSION

• Agomelatine's anxiolytic effects are caused by mechanisms that are distinct from those of other medications currently used to treat GAD.• This explains its therapeutic success and minimal adverse side effects.

Psychedelics as Reemerging Treatments for Anxiety Disorders: Possibilities and Challenges in a Nascent Field

Although psychedelics initially showed promise in treating anxiety disorders, psychedelics were criminalized and research halted in the early 1970s. A subsequent resurgence of research into psychiatric benefits of psychedelic-assisted psychotherapy in the last 20 years has led to a potential paradigm shift in the treatment of numerous psychiatric disorders, including anxiety disorders. Despite accumulating evidence and likely U.S. Food and Drug Administration approval in the next 2-3 years, the emerging field of psychedelic medicine faces several challenges. Obstacles include ongoing barriers on the regulatory level, lack of education, stigma among mental health clinicians, cost and scalability, and a dearth of specialized personnel prepared to provide these treatments. Deeper issues of ethical responsibility and inclusivity also exist given the historical discovery and use of psychedelics by indigenous peoples throughout the world as well the ongoing disparities in mental health delivery and access within psychiatry and psychedelic research.

Adolescent anxiety disorders and the developing brain: comparing neuroimaging findings in adolescents and adults

Adolescence is the peak period for the incidence of anxiety disorders. Recent findings have revealed the immaturity of neural networks underlying emotional regulation in this population. Brain vulnerability to anxiety in adolescence is related to the unsynchronised development of anxiety-relevant brain functional systems. However, our current knowledge on brain deficits in adolescent anxiety is mainly borrowed from studies on adults. Understanding adolescent-specific brain deficits is essential for developing biomarkers and brain-based therapies targeting adolescent anxiety. This article reviews and compares recent neuroimaging literature on anxiety-related brain structural and functional deficits between adolescent and adult populations, and proposes a model highlighting the differences between adolescence and adulthood in anxiety-related brain networks. This model emphasises that in adolescence the emotional control system tends to be hypoactivated, the fear conditioning system is immature, and the reward and stress response systems are hypersensitive. Furthermore, the striatum’s functional links to the amygdala and the prefrontal cortex are strengthened, while the link between the prefrontal cortex and the amygdala is weakened in adolescence. This model helps to explain why adolescents are vulnerable to anxiety disorders and provides insights into potential brain-based approaches to intervene in adolescent anxiety disorders.

Efficacy of Agomelatine 25-50 mg for the Treatment of Anxious Symptoms and Functional Impairment in Generalized Anxiety Disorder: A Meta-Analysis of Three Placebo-Controlled Studies

Introduction

The purpose of this study is to investigate the effects of agomelatine on anxious symptoms and functional impairment in a pooled dataset from randomized placebo-controlled trials for generalized anxiety disorder (GAD).

Methods

Data from three randomized, placebo-controlled trials that evaluated the efficacy of agomelatine 25–50 mg were pooled. The short-term (12 weeks) efficacy of agomelatine was assessed in regards to (1) anxious symptoms using the Hamilton Anxiety Scale (HAM-A), and (2) functional impairment using the Sheehan Disability Scale (SDS). Meta-analysis using a random effect model was used to assess differences between groups. Remission and response rates for the HAM-A and SDS were calculated, and analyses were repeated in participants with more severe anxiety symptoms.

Results

In total, 669 patients (340 on agomelatine; 329 on placebo) were included in the analyses. Compared to placebo, the agomelatine group had a significant reduction in HAM-A total score at week 12 (between group difference: 6.30 ± 2.51, p = 0.012). Significant effects were also found for symptom response on the HAM-A (67.1% of patients on agomelatine vs. 32.5% on placebo) and symptom remission (38.8% of patients on agomelatine vs. 17.3% on placebo). Compared to placebo, there was a significant difference in favour of the agomelatine group at week 12 on the SDS total score (5.11 ± 1.81, p = 0.005). Significant effects were also found for functional response on the SDS (79.1% of patients on agomelatine vs. 43.2% of placebo) and functional remission (55.2% of patients on agomelatine vs. 25.4% on placebo). All findings for anxious symptoms and functional impairment were confirmed in the subset of more severely anxious patients. Agomelatine was well tolerated by patients.

Conclusion

This meta-analysis confirms that agomelatine reduces anxiety symptoms and improves the global functioning of GAD patients.

Supplementary Information

The online version of this article (10.1007/s12325-020-01583-9) contains supplementary material, which is available to authorized users.

Traumatic grief research and care in the aftermath of the COVID-19 pandemic

BACKGROUND

A significant increase in the number of individuals suffering from prolonged grief disorder is expected in the aftermath of the COVID-19 pandemic for two main reasons. First, the number of excess deaths has contributed to an immense number of bereaved individuals. Second, recent literature has shown that circumstances associated with COVID-19 deaths may be contributing to increased risk for the development of prolonged grief disorder.

OBJECTIVE

To best support those affected by loss during the COVID-19 pandemic, it is important to inform clinicians and researchers about the development, the nature and the treatment of prolonged grief disorder and employ sound research.

METHOD

In this editorial, we discuss important themes regarding prolonged grief disorder in the aftermath of the COVID-19 pandemic, to gather and present useful information for clinicians and researchers.

RESULTS

The following themes were addressed: 1. Harmonization in the diagnosis of prolonged grief disorder. 2. Screening tools and interventions. 3. Pharmacotherapy. 4. Special attention for the elderly. 5. Special attention for children and adolescents. 6. A causal system perspective for understanding grief and prolonged grief disorder.

CONCLUSIONS

If those involved in bereavement research and care manage to collaborate, the tragic consequences of COVID-19 might catalyse improvement of care for those most impaired following the loss of a loved one.