Ketamine Assisted Psychotherapy: A Systematic Narrative Review of the Literature

Therapeutic Protocols Using Ketamine and Esketamine for Depressive Disorders: A Systematic Review

Depression is one of the most prevalent mental health disorders globally, causing severe emotional suffering, reducing life expectancy and increasing the risk of suicide. Recently, the use of dissociative psychedelic substances such as ketamine and esketamine for depressive disorders has expanded treatment options. We sought to analyze, through a systematic review, the existing protocols for the treatment of depression with ketamine and esketamine. The search adopted PRISMA criteria and was performed using PubMed and Web of Science databases. Procedures in each study were compared, focusing on the sample recruited, therapeutic approaches, including the clinical team and professionals engaged in treatment, medical procedures, description of the setting (including music) and factors such as specific medication (ketamine or esketamine), route of administration and dosage employed. Results indicated the predominance of a medical approach, with a limited number of studies on ketamine assisted psychotherapy (KAP) and other modalities of psychedelic assisted therapy. Additionally, there is limited information on psychosocial elements such as preparation, psychological support during session and integration of experience. Altogether these findings suggest that treatment of depression with ketamine or esketamine diverges in relation to the practices employed with psychedelic substances. This is discussed considering future research directions in the field.

A novel framework for ketamine-assisted couple therapy

Intimate relationship distress is prevalent and is associated with poorer health, mental health, and mortality outcomes. Evidence-based couple therapies target cognitive, behavioral, and emotional processes that underlie relationship dysfunction. Increasing research and clinical evidence supports the efficacy of ketamine-assisted psychotherapy (KAP) for addressing clinical mental health concerns, including depression, anxiety disorders, posttraumatic stress disorder, and more. The purported mechanisms of KAP are also likely to improve psychosocial and relational functioning for patients and may be useful for supporting change mechanisms in couple therapy. This paper reviews the current evidence for therapeutic ketamine and KAP and outlines how the mechanisms of ketamine therapy may also augment the cognitive, behavioral, and emotional interventions in the most commonly used evidence-based couple therapies. Key mechanisms include increased neuroplasticity, changes in functional connectivity, adaptive dissociation, decreased inhibition, and reduced avoidance. Given the reciprocal interaction between relationship dysfunction and mental health problems, ketamine may also help alleviate relationship distress by directly treating clinical mental health symptoms. We then outline a proposed framework for ketamine-assisted couple therapy, addressing the application of KAP preparation, dosing, and integration to a dyadic intervention framework in a way that can be applied to different couple therapy modalities. This clinical framework for couples' KAP may be useful for clinicians and researchers working to improve the efficacy of couple therapy, particularly when one or both partners has accompanying mental health concerns.

New and emerging treatments for major depressive disorder

Major depressive disorder (MDD) affects a substantial portion of the population; however, much is still unknown about the pathophysiology of this disorder. Treatment resistance highlights the heterogeneous nature of MDD and the need for treatments to target more than monoamine neurotransmission. This review summarizes research into the new and emerging targets of MDD. These include drugs such as psychedelics, antibiotics, opioid modulators, neuropeptides, and onabotulinumtoxin. Neuromodulatory treatments such as light based therapies and neuromodulation involving either magnetic or electrical stimulation are also discussed. Almost all interventions, pharmacological and neuromodulation, were trialed as adjunctive treatments to an antidepressant. Most research has been conducted on psychedelics, with trials suggesting rapid antidepressant and anti-suicidal effects. Trial findings, tolerability, study design limitations and quality of research have been considered throughout this review. There remains challenges in forming recommendations with the current research at present. With there being considerable interest into the research of new and emerging treatments-in particular, psychedelics-there may be scope in the future to form more robust recommendations.

Exploring the impact of music on response to ketamine/esketamine: A scoping review

Music and ketamine are both known to affect therapeutic outcomes, but few studies have investigated their co-administration. This scoping review describes the existing literature on the joint use of music and ketamine-or esketamine (the S(+) enantiomer of ketamine)-in humans. The review considers that extant studies have explored the intersection of ketamine/esketamine and music in healthy volunteers and in patients of various age groups, at different dosages, through different treatment processes, and have varied the sequence of playing music relative to ketamine/esketamine administration. Studies investigating the use of music during ketamine anesthesia are also included in the review because anesthesia and sedation were the early drivers of ketamine use. Studies pertaining to recreational ketamine use were omitted. The review was limited to articles published in the English language but not restricted by publication year. To the best of our knowledge, this scoping review is the first comprehensive exploration of the interplay between music and ketamine/esketamine and offers valuable insights to researchers interested in designing future studies.

Experiences of Awe Mediate Ketamine's Antidepressant Effects: Findings From a Randomized Controlled Trial in Treatment-Resistant Depression

Background

Ketamine, an NMDA receptor antagonist, provides rapid antidepressant effects. Although much research has focused on neural and molecular mechanisms of action, it is critical to also consider psychological mechanisms that may contribute to its therapeutic efficacy. The construct of an awe-inducing experience, which is a well-validated psychological phenomenon tied to emotional well-being, had not been applied previously in ketamine research.

Methods

One hundred sixteen participants with depression, 77 of whom received a ketamine infusion (0.5 mg/kg over 40 minutes) and 39 patients who received saline placebo, completed a validated measure of awe (the Awe Experience Scale [AWE-S]) at 40 minutes postinfusion. AWE-S scores were examined as potential mediators of depression outcomes (% improvement in Montgomery-Åsberg Depression Rating Scale score) at 5 postinfusion time points (24 hours and 5, 12, 21, and 30 days). Dissociative effects, measured by Clinician-Administered Dissociative States Scale scores, were tested in parallel mediation models for comparison.

Results

We found that the psychological experience of awe was strongly reported by participants during ketamine infusion, but not saline infusion, and there were significant associations between total AWE-S scores and Montgomery-Åsberg Depression Rating Scale score improvement (% change) in the ketamine arm at all 5 time points. Furthermore, at all 5 time points, total AWE-S scores statistically mediated the relationship between ketamine and Montgomery-Åsberg Depression Rating Scale scores. By contrast, Clinician-Administered Dissociative States Scale scores did not mediate outcomes at any time point.

Conclusions

Ketamine infusion strongly induced heightened feelings of awe, and these experiences consistently mediated depression outcomes over a 1- to 30-day period, unlike general dissociative side effects. The specific awe-inspiring properties of ketamine may contribute to its antidepressant effects.

Ketamine in the effective management of chronic pain, depression, and posttraumatic stress disorder for Veterans: A meta-analysis and systematic review

Introduction

Ketamine has emerged as a promising treatment alternative for the management of chronic pain. Despite encouraging findings in civilian populations, and favourable results from trials examining its efficacy in military populations, there is still a dearth of information pointing to optimal specifications related to ketamine administration for pain, depression, and posttraumatic stress disorder (PTSD) in military populations. This meta-analysis and systematic review synthesised available evidence on the effectiveness, tolerability, and feasibility of ketamine in the management of chronic pain and mental health conditions in military populations.

Methods

This review followed the Cochrane's Guide for systematic reviews of interventions and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) as frameworks for data collection and synthesis.

Results

A total of 11 studies and 22 independent samples were retained for data analyses. Across samples, improvements in pain, depression, and PTSD outcomes were evident, with the use of ketamine leading to significant reductions, g = 1.76, SE = 0.19, 95% CI (1.39, 2.13), Z = 9.26, p <.001. These effect sizes were robust with moderate-to-large effects. In addition, the reductions in symptoms were observed in both active-duty and Veteran groups, and for different routes of ketamine administration, frequencies of ketamine administration, duration of ketamine treatments, dosage, study design, and allowance for concurrent treatments.

Discussion

This review provides a preliminary synthesis of available evidence which suggests that ketamine may be a potential option for the treatment of depression, PTSD, and chronic pain in military populations. The viability of ketamine as an alternative treatment may be particularly impactful for those who are treatment resistant, experience chronic symptoms, and/or have exhausted conventional treatments. More research is warranted in order verify the findings presented in this review.

Improvement in depressive symptoms in a patient with severe and enduring anorexia nervosa and comorbid major depressive disorder using psychotherapy-assisted IV ketamine : a case report

BACKGROUND

Anorexia nervosa is a life-threatening psychiatric illness with a high mortality rate and limited treatment options. This illness is frequently comorbid with major depressive disorder, leading to additional obstacles in patient quality of life, and increasing the mortality rate further due to risk of suicide. Ketamine, a competitive N-methyl-D-aspartate receptor antagonist, has been shown to be beneficial in depression given its effects on neuroplasticity. There are few cases in the literature describing ketamine use in patients with eating disorders, and even fewer that describe psychotherapy-assisted ketamine use in this patient population. We present the case of a 33-year-old woman with a history of severe and enduring anorexia nervosa and comorbid major depressive disorder who we treated safely with ketamine-assisted psychotherapy using intravenous ketamine in a general hospital setting.

CASE PRESENTATION

Our patient is a 33-year-old woman with past psychiatric history of severe and enduring anorexia nervosa and major depressive disorder with comorbid psychiatric and medical conditions who presented to the hospital due to malnutrition. She had an extensive psychiatric history as well as multiple medical hospitalizations due to her eating disorder. She had tried numerous psychiatric treatments, including antidepressants, mood stabilizers, antipsychotics, electroconvulsive therapy, and multiple types of therapies without significant improvement in symptoms. She agreed to try ketamine for treatment-resistant depression and received it intravenously for seven sessions in a closely monitored setting, and simultaneously engaged in acceptance and commitment therapy during sessions. She demonstrated increased cognitive flexibility, disappearance of suicidal ideation, and reduction in Beck Depression Inventory Scores.

CONCLUSIONS

Our case is unique in that it demonstrates the successful usage of ketamine-assisted psychotherapy in a hospital setting with severe and enduring anorexia nervosa and comorbid major depressive disorder. Her body mass index was profoundly low at 13, whereas the lowest documented in the literature was 16.9. This case shows that ketamine-assisted psychotherapy may be a promising treatment modality for patients with anorexia nervosa with co-morbid depression who have failed other interventions.

Ketamine's Amelioration of Fear Extinction in Adolescent Male Mice Is Associated with the Activation of the Hippocampal Akt-mTOR-GluA1 Pathway

Fear-related disorders, including post-traumatic stress disorder (PTSD), and anxiety disorders are pervasive psychiatric conditions marked by persistent fear, stemming from its dysregulated acquisition and extinction. The primary treatment for these disorders, exposure therapy (ET), relies heavily on fear extinction (FE) principles. Adolescence, a vulnerable period for developing psychiatric disorders, is characterized by neurobiological changes in the fear circuitry, leading to impaired FE and increased susceptibility to relapse following ET. Ketamine, known for relieving anxiety and reducing PTSD symptoms, influences fear-related learning processes and synaptic plasticity across the fear circuitry. Our study aimed to investigate the effects of ketamine (10 mg/kg) on FE in adolescent male C57 BL/6 mice at the behavioral and molecular levels. We analyzed the protein and gene expression of synaptic plasticity markers in the hippocampus (HPC) and prefrontal cortex (PFC) and sought to identify neural correlates associated with ketamine's effects on adolescent extinction learning. Ketamine ameliorated FE in the adolescent males, likely affecting the consolidation and/or recall of extinction memory. Ketamine also increased the Akt and mTOR activity and the GluA1 and GluN2A levels in the HPC and upregulated BDNF exon IV mRNA expression in the HPC and PFC of the fear-extinguished mice. Furthermore, ketamine increased the c-Fos expression in specific brain regions, including the ventral HPC (vHPC) and the left infralimbic ventromedial PFC (IL vmPFC). Providing a comprehensive exploration of ketamine's mechanisms in adolescent FE, our study suggests that ketamine's effects on FE in adolescent males are associated with the activation of hippocampal Akt-mTOR-GluA1 signaling, with the vHPC and the left IL vmPFC as the proposed neural correlates.

Depression with comorbid borderline personality disorder - could ketamine be a treatment catalyst?

Borderline personality disorder (BPD) is diagnosed in 10-30% of patients with major depressive disorder (MDD), and the frequency of MDD among individuals with BPD reaches over 80%. The comorbidity of MDD and BPD is associated with more severe depressive symptoms and functional impairment, higher risk of treatment resistance and increased suicidality. The effectiveness of ketamine usage in treatment resistant depression (TRD) has been demonstrated in numerous studies. In most of these studies, individuals with BPD were not excluded, thus given the high co-occurrence of these disorders, it is possible that the beneficial effects of ketamine also extend to the subpopulation with comorbid TRD and BPD. However, no protocols were developed that would account for comorbidity. Moreover, psychotherapeutic interventions, which may be crucial for achieving a lasting therapeutic effect in TRD and BPD comorbidity, were not included. In the article, we discuss the results of a small number of existing studies and case reports on the use of ketamine in depressive disorders with comorbid BPD. We elucidate how, at the molecular and brain network levels, ketamine can impact the neurobiology and symptoms of BPD. Furthermore, we explore whether ketamine-induced neuroplasticity, augmented by psychotherapy, could be of use in alleviating core BPD-related symptoms such as emotional dysregulation, self-identity disturbances and self-harming behaviors. We also discuss the potential of ketamine-assisted psychotherapy (KAP) in BPD treatment. As there is no standard approach to the application of ketamine or KAP in individuals with comorbid TRD and BPD, we consider further research in the field as imperative. The priorities should include development of dedicated protocols, distinguishing subpopulations that may benefit most from such treatment and investigating factors that may influence its effectiveness and safety.

Psychotherapy for Ketamine's Enhanced Durability in Chronic Neuropathic Pain: Protocol for a Pilot Randomized Controlled Trial

BACKGROUND

Chronic pain affects approximately 8 million Canadians (~20%), impacting their physical and mental health while burdening the health care system with costs of upwards of US $60 billion a year. Indeed, patients are often trialed on numerous medications over several years without reductions to their symptoms. Therefore, there is an urgent need to identify new therapies for chronic pain to improve patients' quality of life, increase the availability of treatment options, and reduce the burden on the health care system.

OBJECTIVE

The primary objective of this study is to examine the feasibility of a parallel 3-arm pilot randomized controlled trial whereby patients are randomized to either intravenous ketamine alone, cognitive behavioral therapy (CBT) and mindfulness meditation (MM) training (CBT/MM), or the combination of intravenous ketamine and CBT/MM. The secondary outcome is to assess the durability and efficacy of combination intravenous ketamine and CBT/MM for treatment of chronic pain as compared to CBT/MM or intravenous ketamine alone (assessed at week 20 of the study).

METHODS

This is a single-center, 16-week, 3-arm pilot study that will take place at the Chronic Pain Clinic at St. Michael's Hospital, Toronto, Ontario, which receives 1000 referrals per year. Patients will be enrolled in the study for a total of 20 weeks. Participants who are allocated CBT/MM therapy will receive remote weekly psychotherapy from week 1 to week 16, inclusive of health coaching administered through the NexJ Health Inc (NexJ Health) platform. Patients who are allocated ketamine-infusion therapy will receive monthly ketamine infusion treatments on weeks 2, 7, and 12. Patients who are allocated ketamine+CBT/MM will receive weekly psychotherapy from weeks 1 to 16, inclusive, as well as ketamine infusion treatments on weeks 2, 7, and 12. We will be assessing recruitment rates, consent rates, withdrawal rates, adherence, missing data, and adverse events as pilot outcome measures. Secondary clinical outcomes include changes relative to baseline in pain intensity and pain interference.

RESULTS

As of November 1, 2023, the recruitment process has not been initiated. Given the recruitment, consent, and intervention target of 30 participants for this feasibility study, with each patient undergoing monitoring and treatments for a course of 20 weeks, we expect to complete the study by December 2025.

CONCLUSIONS

This study assesses the feasibility of conducting a 3-arm randomized controlled trial to examine the effects of ketamine administration with the concurrent use of CBT/MM in a population with chronic neuropathic pain. The results of this pilot randomized controlled trial will inform the development of a larger-scale randomized controlled trial. Future studies will be aimed at including a sufficiently powered sample that will inform decisions about optimal treatment calibration and treatment effect duration.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05639322; https://classic.clinicaltrials.gov/ct2/show/NCT05639322.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/54406.

Targeting metaplasticity mechanisms to promote sustained antidepressant actions

The discovery that subanesthetic doses of (R, S)-ketamine (ketamine) and (S)-ketamine (esketamine) rapidly induce antidepressant effects and promote sustained actions following drug clearance in depressed patients who are treatment-resistant to other therapies has resulted in a paradigm shift in the conceptualization of how rapidly and effectively depression can be treated. Consequently, the mechanism(s) that next generation antidepressants may engage to improve pathophysiology and resultant symptomology are being reconceptualized. Impaired excitatory glutamatergic synapses in mood-regulating circuits are likely a substantial contributor to the pathophysiology of depression. Metaplasticity is the process of regulating future capacity for plasticity by priming neurons with a stimulation that alters later neuronal plasticity responses. Accordingly, the development of treatment modalities that specifically modulate the duration, direction, or magnitude of glutamatergic synaptic plasticity events such as long-term potentiation (LTP), defined here as metaplastogens, may be an effective approach to reverse the pathophysiology underlying depression and improve depression symptoms. We review evidence that the initiating mechanisms of pharmacologically diverse rapid-acting antidepressants (i.e., ketamine mimetics) converge on consistent downstream molecular mediators that facilitate the expression/maintenance of increased synaptic strength and resultant persisting antidepressant effects. Specifically, while the initiating mechanisms of these therapies may differ (e.g., cell type-specificity, N-methyl-D-aspartate receptor (NMDAR) subtype-selective inhibition vs activation, metabotropic glutamate receptor 2/3 antagonism, AMPA receptor potentiation, 5-HT receptor-activating psychedelics, etc.), the sustained therapeutic mechanisms of putative rapid-acting antidepressants will be mediated, in part, by metaplastic effects that converge on consistent molecular mediators to enhance excitatory neurotransmission and altered capacity for synaptic plasticity. We conclude that the convergence of these therapeutic mechanisms provides the opportunity for metaplasticity processes to be harnessed as a druggable plasticity mechanism by next-generation therapeutics. Further, targeting metaplastic mechanisms presents therapeutic advantages including decreased dosing frequency and associated diminished adverse responses by eliminating the requirement for the drug to be continuously present.

Spiritual health practitioners' contributions to psychedelic assisted therapy: A qualitative analysis

BACKGROUND

Psychedelic-assisted therapies hold early promise for treating multiple psychiatric conditions. However, absent standards for the care, teams providing psychedelic-assisted therapy pose a major roadblock to safe administration. Psychedelics often produce spiritually and existentially meaningful experiences, and spiritual health practitioners have been involved in administering psychedelic-assisted therapies in multiple settings, suggesting important qualifications for delivering these therapies. However, the roles and competencies of spiritual health practitioners in psychedelic-assisted therapies have not been described in research.

METHOD

This study examined interviews with 15 spiritual health practitioners who have facilitated psychedelic-assisted therapy. Thematic analyses focused on their contributions, application of expertise and professional background, and roles in administering these therapies.

RESULTS

Seven themes emerged, comprising two domains: unique and general contributions. Unique contributions included: competency to work with spiritual material, awareness of power dynamics, familiarity with non-ordinary states of consciousness, holding space, and offer a counterbalance to biomedical perspectives. General contributions included use of generalizable therapeutic repertoire when conducting PAT, and contributing to interdisciplinary collaboration.

IMPLICATIONS

Spiritual health practitioners bring unique and specific expertise to psychedelic-assisted therapy based on their training and professional experience. They are skilled at interprofessional collaboration in a way that complements other clinical team members. Psychedelic-assisted therapy teams may benefit from including spiritual health practitioners. In order to ensure rigorous standards and quality care, further efforts to delineate the roles and necessary qualifications and training of spiritual health clinicians for psychedelic-assisted therapy are needed.

Psychedelic therapies reconsidered: compounds, clinical indications, and cautious optimism

The clinical investigation of psychedelic medicines has blossomed over the last 5 years. Data from a Phase 3 industry trial and a multicenter Phase 2 industry trial, in addition to multiple early phase investigator-initiated and industry trials, have now been published in peer-reviewed journals. This narrative review summarizes both the recent data and the current clinical trials that are being conducted with various classes of "psyche-manifesting" substances, which may prove beneficial in the treatment of a broad range of conditions. Methodological considerations, unique challenges, and next steps for research are discussed in keeping with the uniquely "experiential" nature of these therapies.

The Stress Phenotyping Framework: A multidisciplinary biobehavioral approach for assessing and therapeutically targeting maladaptive stress physiology

Although dysregulated stress biology is becoming increasingly recognized as a key driver of lifelong disparities in chronic disease, we presently have no validated biomarkers of toxic stress physiology; no biological, behavioral, or cognitive treatments specifically focused on normalizing toxic stress processes; and no agreed-upon guidelines for treating stress in the clinic or evaluating the efficacy of interventions that seek to reduce toxic stress and improve human functioning. We address these critical issues by (a) systematically describing key systems and mechanisms that are dysregulated by stress; (b) summarizing indicators, biomarkers, and instruments for assessing stress response systems; and (c) highlighting therapeutic approaches that can be used to normalize stress-related biopsychosocial functioning. We also present a novel multidisciplinary Stress Phenotyping Framework that can bring stress researchers and clinicians one step closer to realizing the goal of using precision medicine-based approaches to prevent and treat stress-associated health problems.

The Psychedelic Future of Post-Traumatic Stress Disorder Treatment

Post-traumatic stress disorder (PTSD) is a mental health condition that can occur following exposure to a traumatic experience. An estimated 12 million U.S. adults are presently affected by this disorder. Current treatments include psychological therapies (e.g., exposure-based interventions) and pharmacological treatments (e.g., selective serotonin reuptake inhibitors (SSRIs)). However, a significant proportion of patients receiving standard-of-care therapies for PTSD remain symptomatic, and new approaches for this and other trauma-related mental health conditions are greatly needed. Psychedelic compounds that alter cognition, perception, and mood are currently being examined for their efficacy in treating PTSD despite their current status as Drug Enforcement Administration (DEA)- scheduled substances. Initial clinical trials have demonstrated the potential value of psychedelicassisted therapy to treat PTSD and other psychiatric disorders. In this comprehensive review, we summarize the state of the science of PTSD clinical care, including current treatments and their shortcomings. We review clinical studies of psychedelic interventions to treat PTSD, trauma-related disorders, and common comorbidities. The classic psychedelics psilocybin, lysergic acid diethylamide (LSD), and N,N-dimethyltryptamine (DMT) and DMT-containing ayahuasca, as well as the entactogen 3,4-methylenedioxymethamphetamine (MDMA) and the dissociative anesthetic ketamine, are reviewed. For each drug, we present the history of use, psychological and somatic effects, pharmacology, and safety profile. The rationale and proposed mechanisms for use in treating PTSD and traumarelated disorders are discussed. This review concludes with an in-depth consideration of future directions for the psychiatric applications of psychedelics to maximize therapeutic benefit and minimize risk in individuals and communities impacted by trauma-related conditions.

Ketamine-Assisted Psychodynamic Psychotherapy

This case report details the treatment of a longtime psychodynamic psychotherapy patient, with a particular focus on a ketamine-assisted psychotherapy (KAP) session, and how the progress achieved during this session compares with the literature on KAP. The patient is a 54-year-old woman with a history of multiple traumas, including sexual assault and life-threatening physical injuries, as well as a recent diagnosis of primary lateral sclerosis (PLS). For most of her life, she relied on extreme idealization of important people in her life as her primary defense mechanism, helping her to maintain physical and psychological survival. However, after a KAP session in January 2023 she discovered the consequences of her extreme idealizing tendencies. Among these was the creation of troubling double binds for the people she idealized, as well as the fomentation of conflict between these individuals with each other. Also unconscious was the secondary gain offered by her escalating physical symptoms and pain-that is, the ability to resolve conflicts between those she idealized-and how this secondary gain increased the likelihood of symptom exacerbations during periods of conflict. After the discovery of these unconscious tendencies during her KAP session, the patient has since been able to avoid extreme idealization of important people in her life and has subsequently experienced fewer episodes of exacerbation of her physical symptoms. Consistent with the opinions of clinicians and researchers published in the literature, the achievement of a psychedelic trance state appeared necessary for the success of the patient's KAP treatment.

Courtes A, Jones G, Soares JC, Machado-Vieira R. Pharmacotherapies Targeting GABA-Glutamate Neurotransmission for Treatment-Resistant Depression

Treatment-resistant depression (TRD) is a term used to describe a particular type of major depressive disorder (MDD). There is no consensus about what defines TRD, with various studies describing between 1 and 4 failures of antidepressant therapies, with or without electroconvulsive therapy (ECT). That is why TRD is such a growing concern among clinicians and researchers, and it explains the necessity for investigating novel therapeutic targets beyond conventional monoamine pathways. An imbalance between two primary central nervous system (CNS) neurotransmitters, L-glutamate and γ-aminobutyric acid (GABA), has emerged as having a key role in the pathophysiology of TRD. In this review, we provide an evaluation and comprehensive review of investigational antidepressants targeting these two systems, accessing their levels of available evidence, mechanisms of action, and safety profiles. N-methyl-D-aspartate (NMDA) receptor antagonism has shown the most promise amongst the glutamatergic targets, with ketamine and esketamine (Spravato) robustly generating responses across trials. Two specific NMDA-glycine site modulators, D-cycloserine (DCS) and apimostinel, have also generated promising initial safety and efficacy profiles, warranting further investigation. Combination dextromethorphan-bupropion (AXS-05/Auvelity) displays a unique mechanism of action and demonstrated positive results in particular applicability in subpopulations with cognitive dysfunction. Currently, the most promising GABA modulators appear to be synthetic neurosteroid analogs with positive GABAA receptor modulation (such as brexanolone). Overall, advances in the last decade provide exciting perspectives for those who do not improve with conventional therapies. Of the compounds reviewed here, three are approved by the Food and Drug Administration (FDA): esketamine (Spravato) for TRD, Auvelity (dextromethorphan-bupropion) for major depressive disorder (MDD), and brexanolone (Zulresso) for post-partum depression (PPD). Notably, some concerns have arisen with esketamine and brexanolone, which will be detailed in this study.

Psychedelics in the treatment of eating disorders: Rationale and potential mechanisms

Eating disorders are serious illnesses showing high rates of mortality and comorbidity with other mental health problems. Psychedelic-assisted therapy has recently shown potential in the treatment of several common comorbidities of eating disorders, including mood disorders, post-traumatic stress disorder, and substance use disorders. The theorized therapeutic mechanisms of psychedelic-assisted therapy suggest that it could be beneficial in the treatment of eating disorders as well. In this review, we summarize preliminary data on the efficacy of psychedelic-assisted therapy in people with anorexia nervosa, bulimia nervosa, and binge eating disorder, which include studies and case reports of psychedelic-assisted therapy with ketamine, MDMA, psilocybin, and ayahuasca. We then discuss the potential therapeutic mechanisms of psychedelic-assisted therapy in these three eating disorders, including both general therapeutic mechanisms and those which are relatively specific to eating disorders. We find preliminary evidence that psychedelic-assisted therapy may be effective in the treatment of anorexia nervosa and bulimia nervosa, with very little data available on binge eating disorder. Regarding mechanisms, psychedelic-assisted therapy may be able to improve beliefs about body image, normalize reward processing, promote cognitive flexibility, and facilitate trauma processing. Just as importantly, it appears to promote general therapeutic factors relevant to both eating disorders and many of their common comorbidities. Lastly, we discuss potential safety concerns which may be associated with these treatments and present recommendations for future research.

Long term structural and functional neural changes following a single infusion of Ketamine in PTSD

NMDA receptor antagonists have a vital role in extinction, learning, and reconsolidation processes. During the reconsolidation window, memories are activated into a labile state and can be reconsolidated in an altered form. This concept might have significant clinical implications in treating PTSD. In this pilot study we tested the potential of a single infusion of ketamine, followed by brief exposure therapy, to enhance post-retrieval extinction of PTSD trauma memories. 27 individuals diagnosed with PTSD were randomly assigned to receive either ketamine (0.5 mg/kg 40 min; N = 14) or midazolam (0.045 mg/kg; N = 13) after retrieval of the traumatic memory. 24 h following infusion, participants received a four-day trauma-focused psychotherapy. Symptoms and brain activity were assessed before treatment, at the end of treatment, and at 30-day follow-up. Amygdala activation to trauma scripts (a major biomarker of fear response) served as the main study outcome. Although PTSD symptoms improved equally in both groups, post-treatment, ketamine recipients showed a lower amygdala (-0.33, sd = 0.13, 95%HDI [-0.56,-0.04]) and hippocampus (-0.3 (sd = 0.19), 95%HDI [-0.65, 0.04]; marginal effect) reactivation to trauma memories, compared to midazolam recipients. Post-retrieval ketamine administration was also associated with decreased connectivity between the amygdala and hippocampus (-0.28, sd = 0.11, 95%HDI [-0.46, -0.11]), with no change in amygdala-vmPFC connectivity. Moreover, reduction in fractional anisotropy in bi-lateral uncinate fasciculus was seen in the Ketamine recipients compared with the midazolam recipients (right: post-treatment: -0.01108, 95% HDI [-0.0184,-0.003]; follow-up: -0.0183, 95% HDI [-0.02719,-0.0107]; left: post-treatment: -0.019, 95% HDI [-0.028,-0.011]; follow-up: -0.017, 95% HDI [-0.026,-0.007]). Taken together it is possible that ketamine may enhance post-retrieval extinction of the original trauma memories in humans. These preliminary findings show promising direction toward the capacity to rewrite human traumatic memories and modulate the fear response for at least 30 days post-extinction. When combined with psychotherapy for PTSD, further investigation of ketamine dose, timing of administration, and frequency of administration, is warranted.

A Pilot Study Comparing a Community of Practice Program with and without Concurrent Ketamine-Assisted Therapy

The prevalence of depression, anxiety, and post-traumatic stress disorder (PTSD) has increased among healthcare providers, while the effectiveness of conventional treatments remains limited. Ketamine-assisted therapy offers a promising alternative; however, few have integrated ketamine with a group-based therapeutic modality. We report a retrospective, secondary analysis of a 12-week pilot of a Community of Practice (CoP) oriented group therapy program with optional, adjunct ketamine for depression, anxiety, and PTSD in a sample of 57 healthcare providers. All participants moved through the treatment as one group, with 38 electing to also receive three adjunct ketamine sessions in addition to the weekly CoP. Symptoms were assessed at baseline and pilot completion with the PHQ-9 for depression, GAD-7 for anxiety, and PCL-5 for PTSD. We observed significant reductions in the mean change among all participants, suggesting that benefit was derived from the CoP component, with or without ketamine as an adjunct. PHQ-9 scores decreased by 6.79 (95% CI: 5.09-8.49, p < .001), GAD-7 scores decreased by 5.57 (CI: 4.12-7.00, p < .001), and PCL-5 scores decreased by 14.83 (CI: 10.27-19.38, p < .001). Reductions were larger, but statistically nonsignificant, among those receiving ketamine. Further research is required to assess the impact of ketamine as an adjunct in group-based therapies.

Reductions in anxiety and depression symptoms in a subset of outpatients with problematic substance use who received ketamine-assisted psychotherapy: a two-year retrospective chart review

Objective

Assess changes in symptoms of anxiety, depression, and psychosocial or spiritual distress before and after ketamine-assisted psychotherapy (KAP) in individuals with problematic substance use (PSU).

Methods

A retrospective chart review was performed on participant data from two five-year prospective outcomes studies: the AIMS Medical Outcomes Study (AMOS) and the AIMS Cancer Outcomes Study (ACOS). The efficacy of KAP for anxiety, depression, and psychosocial or spiritual well being was assessed in patients with current, past, or high risk of substance use disorder. Validated psychometrics utilized were Generalized Anxiety Disorder-7 (GAD-7), Patient Health Questionnaire-9 (PHQ-9), and the National Institute of Health - Healing Experiences of All Life Stressors (NIH-HEALS) questionnaires.

Results

Between November 1, 2020 and October 31, 2022, a total of 18 patients identified with problematic substance use completed at least one KAP session and at least one baseline and post-KAP metric questionnaire. The PSU subpopulation average score changes were as follows: GAD-7 (-6.71 ± 9.15, n = 14); PHQ-9 (-7.44 ± 5.42, n = 16); and NIH-HEALS (5.13 ± 13.64, n = 15). The average score changes for the KAP population of enrolled subjects were as follows: GAD-7 (-2.45 ± 6.01, n = 104); PHQ-9 (-3.02 ± 6.01, n = 111); and NIH-HEALS (2.93 ± 11.91, n = 86). A comparison of average score changes (p < 0.05) between the PSU subpopulation and KAP population were as follows: GAD-7 (0.0219, 95% C.I. 1.37-8.11); PHQ-9 (0.0062, 95% C.I. 1.28-7.56); and NIH-HEALS (0.5197, 95% C.I. 8.96-4.56). For patients with PSU, results demonstrate statistically significant improvements in anxiety and depression symptoms after at least one KAP session. Average NIH-HEALS scores increased, though not by a statistically significant amount. Compared to the general population of enrolled KAP patients during this period, patients with PSU reported significantly greater average reductions in GAD-7 and PHQ-9 scores.

Conclusion

Undergoing one to six ketamine-assisted psychotherapy (KAP) sessions was associated with improved anxiety and depression ratings in patients with problematic substance use. Two-thirds of participants also experienced improved psychosocial and spiritual well-being. The use of KAP may be important to consider as a therapy for reducing anxiety and depression symptoms in patients with problematic substance use.

Developing non-opioid therapeutics to alleviate pain among persons with opioid use disorder: a review of the human evidence

The opioid crisis remains a major public health concern, causing significant morbidity and mortality worldwide. Pain is frequently observed among individuals with opioid use disorder (OUD), and the current opioid agonist therapies (OAT) have limited efficacy in addressing the pain needs of this population. We reviewed the most promising non-opioid analgesic therapies for opioid-dependent individuals synthesising data from randomised controlled trials in the Medline database from December 2022 to March 2023. Ketamine, gabapentin, serotoninergic antidepressants, and GABAergic drugs were found to be the most extensively studied non-opioid analgesics with positive results. Additionally, we explored the potential of cannabinoids, glial activation inhibitors, psychedelics, cholecystokinin antagonists, alpha-2 adrenergic agonists, and cholinergic drugs. Methodological improvements are required to advance the development of novel analgesic strategies and establish their safety profile for opioid-dependent populations. We highlight the need for greater integration of experimental pain methods and abuse liability assessments, more granular assessments of prior opioid exposure, greater uniformity of pain types within study samples, and a particular focus on individuals with OUD receiving OAT. Finally, future research should investigate pharmacokinetic interactions between OAT and various non-opioid analgesics and perform reverse translation basic experiments, particularly with methadone and buprenorphine, which remain the standard OUD treatment.

Measuring acute effects of subanesthetic ketamine on cerebrovascular hemodynamics in humans using TD-fNIRS

Quantifying neural activity in natural conditions (i.e. conditions comparable to the standard clinical patient experience) during the administration of psychedelics may further our scientific understanding of the effects and mechanisms of action. This data may facilitate the discovery of novel biomarkers enabling more personalized treatments and improved patient outcomes. In this single-blind, placebo-controlled study with a non-randomized design, we use time-domain functional near-infrared spectroscopy (TD-fNIRS) to measure acute brain dynamics after intramuscular subanesthetic ketamine (0.75 mg/kg) and placebo (saline) administration in healthy participants (n = 15, 8 females, 7 males, age 32.4 ± 7.5 years) in a clinical setting. We found that the ketamine administration caused an altered state of consciousness and changes in systemic physiology (e.g. increase in pulse rate and electrodermal activity). Furthermore, ketamine led to a brain-wide reduction in the fractional amplitude of low frequency fluctuations, and a decrease in the global brain connectivity of the prefrontal region. Lastly, we provide preliminary evidence that a combination of neural and physiological metrics may serve as predictors of subjective mystical experiences and reductions in depressive symptomatology. Overall, our study demonstrated the successful application of fNIRS neuroimaging to study the physiological effects of the psychoactive substance ketamine in humans, and can be regarded as an important step toward larger scale clinical fNIRS studies that can quantify the impact of psychedelics on the brain in standard clinical settings.

Ketamine for Treatment of Posttraumatic Stress Disorder: State of the Field

Posttraumatic stress disorder (PTSD) is a chronic and debilitating condition. Although several psychotherapeutic and pharmacological treatments are recommended for PTSD, many individuals do not respond to treatment or respond only partially, highlighting a critical need for additional treatments. Ketamine has the potential to address this therapeutic need. This review discusses how ketamine emerged as a rapid-acting antidepressant and has become a potential treatment for PTSD. A single dose of intravenous (IV) ketamine has been shown to facilitate rapid reduction of PTSD symptoms. Repeated IV ketamine administration significantly improved PTSD symptoms, compared with midazolam, in a predominantly civilian sample of individuals with PTSD. However, in a veteran and military population, repeated IV ketamine did not significantly reduce PTSD symptoms. Further study of ketamine as a treatment for PTSD is necessary, including which populations benefit most from this therapy and the potential benefits of combining psychotherapy and ketamine.

Phenomenology and therapeutic potential of patient experiences during oral esketamine treatment for treatment-resistant depression: an interpretative phenomenological study

BACKGROUND

Ketamine and its enantiomers are widely researched and increasingly used to treat mental disorders, especially treatment-resistant depression. The phenomenology of ketamine-induced experiences and their relation to its psychotherapeutic potential have not yet been systematically investigated.

AIMS

To describe the phenomenology of patient experiences during oral esketamine treatment for treatment-resistant depression (TRD) and to explore the potential therapeutic relevance of these experiences.

METHODS

In-depth interviews were conducted with 17 patients after a 6-week, twice-weekly 'off label' generic oral esketamine (0.5-3.0mg/kg) treatment program. Interviews explored participants' perspectives, expectations, and experiences with oral esketamine treatment. Audio interviews were transcribed and analyzed using an Interpretative Phenomenological Analysis (IPA) framework.

RESULTS

The effects of ketamine were highly variable, and psychological distress was common in most patients. Key themes included (a) perceptual effects (auditory, visual, proprioceptive), (b) detachment (from body, self, emotions, and the world), (c) stillness and openness, (d) mystical-type effects (transcendence, relativeness, spirituality), and (e) fear and anxiety. Key themes related to post-session reports included (a) feeling hungover and fatigued, and (b) lifting the blanket: neutralizing mood effects.

CONCLUSION

Patients reported several esketamine effects with psychotherapeutic potential, such as increased openness, detachment, an interruption of negativity, and mystical-type experiences. These experiences deserve to be explored further to enhance treatment outcomes in patients with TRD. Given the frequency and severity of the perceived distress, we identify a need for additional support in all stages of esketamine treatment.

The therapeutic use and efficacy of ketamine in alcohol use disorder and alcohol withdrawal syndrome: a scoping review

Introduction

Alcohol use disorder (AUD) is the most prevalent substance use disorder (SUD) globally. In 2019, AUD affected 14.5 million Americans and contributed to 95,000 deaths, with an annual cost exceeding 250 billion dollars. Current treatment options for AUD have moderate therapeutic effects and high relapse rates. Recent investigations have demonstrated the potential efficacy of intravenous ketamine infusions to increase alcohol abstinence and may be a safe adjunct to the existing alcohol withdrawal syndrome (AWS) management strategies.

Methods

We followed Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines to conduct a scoping review of two databases (PubMed and Google Scholar) for peer-reviewed manuscripts describing the use of ketamine in AUD and AWS. Studies that evaluated the use of ketamine in AUD and AWS in humans were included. We excluded studies that examined laboratory animals, described alternative uses of ketamine, or discussed other treatments of AUD and AWS.

Results

We identified 204 research studies in our database search. Of these, 10 articles demonstrated the use of ketamine in AUD or AWS in humans. Seven studies investigated the use of ketamine in AUD and three studies described its use in AWS. Ketamine used in AUD was beneficial in reducing cravings, alcohol consumption and longer abstinence rates when compared to treatment as usual. In AWS, ketamine was used as an adjunct to standard benzodiazepine therapy during severe refractory AWS and at signs of delirium tremens. Adjunctive use of ketamine demonstrated earlier resolution of delirium tremens and AWS, reduced ICU stay, and lowered likelihood of intubation. Oversedation, headache, hypertension, and euphoria were the documented adverse effects after ketamine administration for AUD and AWS.

Conclusion

The use of sub-dissociative doses of ketamine for the treatment of AUD and AWS is promising but more definitive evidence of its efficacy and safety is required before recommending it for broader clinical use.

Reconsidering "dissociation" as a predictor of antidepressant efficacy for esketamine

RATIONALE

The relationship between subjective drug experience and antidepressant outcomes for ketamine derivatives is poorly understood but of high clinical relevance. Esketamine is the patented (S)-enantiomer of ketamine and has regulatory approval for psychiatric applications.

OBJECTIVES

We examined the relationship between acute dissociation, as measured by the Clinician-Administered Dissociative States Scale (CADSS), and antidepressant efficacy, as measured by the Montgomery-Åsberg Depression Rating Scale (MADRS), for esketamine across the 4-week induction phase of treatment.

METHODS

This post hoc analysis combined data (N = 576) from the TRANSFORM-1 and TRANSFORM-2 clinical trials of esketamine for treatment-resistant depression. Linear mixed models were performed using total MADRS score as the outcome variable with the following independent variables: baseline MADRS score, treatment condition × time interaction, and CADSS × time interaction. To assess whether initial dissociation predicted rapid antidepressant benefit with esketamine, a separately planned regression was performed with day 2 MADRS as the outcome variable with the following dependent variables: baseline MADRS, treatment condition, and day 1 CADSS.

RESULTS

The linear mixed model did not show any effect of a CADSS × time interaction (p = 0.7). Looking solely at the effect of day 1 CADSS on day 2 MADRS revealed that each additional CADSS point was associated with a - .04 [95% CI - .08, - .002] (p = .04) decrease in MADRS score.

CONCLUSIONS

We found no evidence of a clinically significant positive or negative association between dissociation and antidepressant effect for esketamine. Our findings suggest that subsequent inquiry in this area will benefit from improved characterization of drug experiences relevant to therapeutic outcomes.

Case report: Medical student types journals during ketamine infusions for suicidal ideation, treatment-resistant depression, post-traumatic stress disorder, and generalized anxiety disorder

Suicide is the most common cause of death in male resident physicians and the second most common cause of death in resident physicians overall. Physicians also experience high rates of major depressive disorder (MDD), post-traumatic stress disorder (PTSD), and burnout. These conditions frequently develop during medical school, and threaten not only physicians but the patients they care for. A 30-year-old medical student presented to our clinic with a history of treatment-resistant depression (TRD), generalized anxiety disorder (GAD), PTSD, and 5 years of daily suicidal ideation. Previous treatments included therapy, lifestyle modifications, and various combinations of six antidepressants. These interventions had little effect on the patient's mental health. The patient was treated at our clinic with an 8-month regimen of IV ketamine infusions and ketamine-assisted psychotherapy (KAP). The patient achieved remission from suicidality and PTSD within 1 month; and TRD and GAD within 7 months. The patient's Patient Health Questionnaire (PHQ-9) score decreased from 25 (severe depression) to 1 (not depressed). These findings suggest that ketamine and KAP may represent effective interventions for mental health applications in healthcare professionals. The patient made the unique decision to attempt to type narrative journals during four of his ketamine infusions (doses ranged from 1.8 to 2.1 mg/kg/h IV). The patient successfully typed detailed journals throughout each 1-h ketamine infusion. To our knowledge, these journals represent the first independently typed, first-person, real-time narratives of ketamine-induced non ordinary states of consciousness. The transcripts of these journals may provide useful insights for clinicians, particularly in the context of KAP.