Serotonergic psychedelics, such as lysergic acid diethylamide, and psilocybin, and the entactogen 3,4-methylenedioxymethamphetamine exhibit agonist activity at the 5-hydroxytryptamine 2B receptor, a signalling pathway known to mechanistically mediate drug-induced valvular heart disease. This systematic review evaluates whether chronic or repeated use of psychedelics and...
Convergent evidence suggests that disrupted reward processing may be associated with observed alterations in frontostriatal activity in persons with major depressive disorder (MDD). Replicated evidence suggests that glutamatergic modulators may benefit persons experiencing disrupted reward function compared to healthy controls (HC). Herein, we systematically reviewed functional magnetic...
Up to 50% of adults with major depressive disorder (MDD) fail to achieve remission after two or more monoaminergic antidepressants and meet criteria for treatment-resistant depression (TRD). Low-dose intravenous ketamine, intranasal esketamine, and oral dextromethorphan represent the first glutamatergic treatments to exhibit rapid and robust efficacy in persons with TRD, yet their precise...
The reported mixed findings suggest that the opioid system may exert a partial mediating effect of ketamine in TRD. However, given the inconsistent attenuation of ketamine's antidepressant effects by opioid receptor antagonists, the opioid system likely functions as a context-dependent modulator rather than a primary mediator, particularly at standard antidepressant doses.
Treatment-resistant depression (TRD) remains a major clinical challenge, and long-term real-world data on intranasal esketamine are limited. To describe long-term dosing patterns and clinical outcomes associated with intranasal esketamine in routine clinical practice. Single-center observational cohort study with descriptive analyses. We analyzed 45 patients with TRD treated with intranasal...
Ketamine is a dissociative anesthetic with potential for treating mood, anxiety, and related disorders; however, concerns have emerged regarding hepatotoxicity in the context of chronic treatment. Systematic searches of PubMed, Scopus, and Ovid databases were conducted from inception to August 2025. Eligible studies included randomized controlled trials (RCTs), observational studies, and case...
Dextromethorphan/Buproprion (DXM/BUP) has received breakthrough FDA approval in August 2022 as a rapid-acting antidepressant. DXM/BUP is a noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist and sigma-1 receptor agonist, with bupropion (BUP), a norepinephrine/dopamine reuptake inhibitor and cytochrome P450 2D6 (CYP2D6) inhibitor. As DXM/BUP moves closer to widespread clinical use for...
ABSTRACT Introduction Posttraumatic stress disorder (PTSD) is a mental disorder resulting from exposure to traumatic events. Evidence suggests that ketamine may be efficacious in treating PTSD, however, ketamine's mechanisms in treating PTSD remain unclear. Herein, this review aims to evaluate the clinical outcomes of ketamine treatment in persons with PTSD and investigate the possible...
PAP was associated with modest, short-term improvements in performance on measures of processing speed and executive function among individuals with TRD. While these changes appeared independent of mood, they did not consistently exceed expected practice effects. These findings highlight the need for adequately powered, controlled trials to clarify whether observed cognitive changes reflect...
INTRODUCTION: Functional impairment is commonly reported amongst individuals with major depressive disorder (MDD) or treatment-resistant depression (TRD). Extant evidence suggests that ketamine and esketamine, N-methyl-D-aspartate (NMDA) receptor antagonists and glutamatergic modulators, have shown efficacy in treating MDD/TRD. While symptom reduction remains central to treatment, many...
Our results suggest that NMDAR antagonism improves alpha and beta cell function and viability, which may have translational relevance to comorbid metabolic dysfunction in depression. These mechanisms may subserve the antidepressant effects of select NMDA antagonists (e.g., ketamine/esketamine, dextromethorphan). Further research should aim to investigate the effects of subanesthetic doses of...
There has been a renewed interest in the use of various psychedelic agents as potential therapies for multiple psychiatric conditions, including post-traumatic stress disorder (PTSD), major depressive disorder (MDD), generalized anxiety disorder (GAD), to name a few. This follows the recent accumulation of evidence for ketamine pharmacotherapy and a rapid proliferation of clinics/programs...
Although these findings suggest psilocybin is associated with dynamic and temporally distinct neuroplastic changes linked to clinical improvement, several limitations must be acknowledged. Many studies reused overlapping datasets with high exploratory flexibility and risk of bias. The generalizability of results is therefore constrained. Future research should emphasize independent datasets,...
Antidepressant effects with sub-anesthetic doses of intravenous ketamine have been previously demonstrated. However, previous studies have primarily evaluated the efficacy of acute treatment protocols, with limited research on maintenance treatment. Moreover, controlled maintenance studies have only included patients with treatment-resistant Major Depressive Disorder (TRD), with no maintenance...
G protein-coupled receptors (GPCRs) are involved in many physiological and pathophysiological processes. Conventional pharmacological models categorize the typology of pharmacologic ligands as agonists or antagonists. Biased agonism is a relatively newer pharmacodynamic characteristic that has potential to optimize therapeutic efficacy while minimizing adverse effects in psychiatric and...
The rapid and clinically meaningful antidepressant effects of ketamine and esketamine are well-established in major depressive disorder (MDD) and treatment-resistant depression (TRD) as evidenced by improvement in clinician- and patient-reported depression measures. However, there remains a need to determine how these agents affect patient-reported quality of life (QoL). Herein, we aimed to...
Ketamine has emerged as a promising treatment for major depression, though its efficacy and safety remain incompletely characterized in older adults. This systematic review synthesizes current evidence for ketamine in geriatric depression. A search of PubMed, EMBASE, and PsycINFO was conducted. Prospective clinical trials were included, with age restriction to participants ≥60 years applied at...
INTRODUCTION Anhedonia, defined as the diminished ability to experience or anticipate pleasure, is a core symptom of major depressive disorder (MDD) and bipolar depression (BD), and associated with depression severity, suicidality and poor treatment outcomes. Conventional antidepressants demonstrate limited efficacy against anhedonia. Esketamine nasal spray (ESK-NS) - a novel NMDA receptor...
Holistic management of persons living with Major Depressive Disorder (MDD) and Bipolar Disorder (BD) invites the need for evaluation of positive mental health (PMH; pleasure attainment and meaning-in-life), alongside conventional measures of psychopathology. The aforementioned dimensions of PMH involve aspects of mindfulness and grit. Herein, we evaluate these aspects using ecological momentary...
Background: Ketamine and esketamine have been reported to rapidly alleviate various parameters of suicidality, with antisuicidal effects that may be independent of their rapid-acting antidepressant effects. However, it remains unclear whether ketamine and/or esketamine are associated with the emergence or worsening of suicidality. Methods: In this global observational pharmacovigilance cohort...
Background: Psilocybin-assisted psychotherapy (PAP) is a promising treatment for various psychiatric disorders. However, the exact biological and psychological mechanisms of action of PAP remain to be determined. Examining predictors of PAP outcomes may help identify necessary processes for positive treatment outcomes. Mystical experiences are considered a key aspect of the subjective effects...
The mechanism of action of antidepressants is not fully ascertained. In addition to monoamines, disparate other effectors are also implicated in the molecular and cellular effects of chronic stress including neurogenesis, neurodifferentiation, and neuroplasticity. Evidence suggests sigma-1 receptors (S1Rs) as a putative target and possible mediator of antidepressant activity. Data from...
Psychedelics have re-emerged as promising treatments for mood disorders. The current model provides a moderate-to-high dose of a psychedelic agent (e.g., psilocybin) to reliably induce an altered state of consciousness. Unfortunately, the hallucinatory effects limit the treatment's potential scalability given patients' vulnerability and extensive monitoring costs, leading to growing interest in...
Childhood trauma is a well‐established risk factor for major depressive disorder (MDD) and is often associated with attenuated response to conventional antidepressant therapies. Ketamine has emerged as an effective treatment for treatment‐resistant depression (TRD), but the impact of childhood trauma on its effectiveness remains unclear. Herein, we aimed to determine whether childhood trauma...
Patients with treatment resistant depression (TRD) experience a greater negative impact on their functioning and productivity at home and in the workplace versus treatment-responsive patients. Here, we report the effects of esketamine nasal spray (NS) versus quetiapine extended release (XR) on functioning, work productivity and activity impairment. ESCAPE‑TRD (NCT04338321) was a 32-week...