Registered clinical trials investigating ketamine for psychiatric disorders

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.

Oral ketamine for depression: An updated systematic review

Objectives: Ketamine is a glutamate N-methyl-D-aspartate receptor antagonist that can be used to treat major depressive disorder by single or repeated infusions. However, the accessibility and scalability of oral ketamine make it preferred over intravenous ketamine. In this systematic review, we aim to evaluate the efficacy, tolerability, and safety of oral ketamine, esketamine and r-ketamine for unipolar and bipolar depression. Materials and methods: Electronic databases were searched from inception to September 2022 to identify relevant articles. Results: Twenty-two studies, including four randomized clinical trials (RCTs), one case series, six case reports, five open-label trials and six retrospective chart review studies involving 2336 patients with depression were included. All included studies reported significant improvement following ketamine administration. Ketamine was well tolerated without serious adverse events. However, RCTs had a high risk of bias due to analysis methods and adverse events monitoring. Ketamine dosage varied from 0.5 to 1.25 mg/kg. The frequency of administration was daily to monthly. Several important limitations were identified, most notably the small number of RCTs. Conclusions: Taken together, preliminary evidence suggests the potential for antidepressant effect of oral ketamine. However, further research with large sample size and long follow-up period is needed to better determine the antisuicidal effect and efficacy in treatment-resistant depression.

Esketamine vs Midazolam in Boosting the Efficacy of Oral Antidepressants for Major Depressive Disorder: A Pilot Randomized Clinical Trial

Importance

Loss of a previously effective response while still using adequate antidepressant treatment occurs in a relatively high proportion of patients with major depressive disorder (MDD); therefore, there is a need to develop novel effective treatment strategies.

Objective

To assess the efficacy and safety of a single subanesthetic dose of esketamine in boosting the efficacy of oral antidepressants for treating fluctuating antidepressant response in MDD.

Design, Setting, and Participants

This single-center, double-blind, midazolam-controlled pilot randomized clinical trial was conducted at Beijing Anding Hospital, Capital Medical University in China. The study enrolled participants aged 18 years and older with fluctuating antidepressant response, defined as patients with MDD experiencing fluctuating symptoms after symptom relief and stabilization. Patient recruitment was conducted from August 2021 to January 2022, and participants were followed-up for 6 weeks. Data were analyzed as intention-to-treat from July to September 2022.

Interventions

All participants in the esketamine-treated group received intravenous esketamine at 0.2 mg/kg in 40 minutes. Participants in the midazolam control group received intravenous midazolam at 0.045 mg/kg in 40 minutes.

Main Outcomes and Measures

The primary outcome was the response rate at 2 weeks, defined as a 50% reduction in Montgomery-Åsberg Depression Rating Scale (MADRS). Secondary outcomes included response rate at 6 weeks, remission rates at 2 and 6 weeks, and change in MADRS and Clinical Global Impression-Severity score from baseline to 6 weeks; remission was defined by a MADRS score of 10 or lower.

Results

A total of 30 patients (median [IQR] age, 28.0 [24.0-40.0] years; 17 [56.7%] female) were randomized, including 15 patients randomized to midazolam and 15 patients randomized to esketamine; 29 patients completed the study. Response rates at 2 weeks were significantly higher in the esketamine-treated group than in the midazolam control group (10 patients [66.7%] vs 1 patient [6.7%]; P < .001). Participants treated with esketamine experienced significantly greater reduction in MADRS score from baseline to 2 weeks compared with those treated with midazolam (mean [SD] reduction, 15.7 [1.5] vs 3.1 [1.3]; P < .001). No serious adverse events were observed in this trial, and no psychotogenic effects and clinically significant manic symptoms were reported.

Conclusions and Relevance

This pilot randomized clinical trial found that a single subanesthetic dose of esketamine could boost the efficacy of oral antidepressants in treating fluctuating antidepressant response, with a good safety profile.

Trial Registration

Chinese Clinical Trial Registry Identifier: ChiCTR2100050335.

Real-world effectiveness of repeated ketamine infusions for treatment-resistant bipolar depression

BACKGROUND

Clinical trials have demonstrated rapid antidepressant effects with intravenous (IV) ketamine for major depressive disorder, with relatively less research specifically for bipolar depression. Herein, we describe the real-world effectiveness of repeated ketamine infusions for treatment-resistant bipolar depression.

METHODS

This study was conducted in a community clinic in Mississauga, Ontario (Canadian Rapid Treatment Centre of Excellence; Braxia Health). In this observational study (NCT04209296), patients with treatment-resistant bipolar I/II depression (n = 66) received four sub-anesthetic doses of IV ketamine (0.5-0.75 mg/kg) over a two-week period. Symptoms of depression, suicidality, anxiety, and functioning were assessed with validated self-report measures.

RESULTS

Statistically and clinically significant antidepressant effects were observed in the overall sample, as measured by the Quick Inventory for Depression Symptomatology-Self Report-16 (QIDS-SR16 ) with further reductions in depressive symptoms observed after each subsequent infusion (n = 66; mean QIDS-SR16 reduction of 6.08+/-1.39; p < 0.0001). Significant reductions of suicidal thoughts (QIDS-SR16 -Suicide Item) and anxiety (Generalized Anxiety Disorder-7) were also observed with functional improvements on the Sheehan Disability Scale (p < 0.0001 on all measures). Moreover, the response rate (QIDS-SR16 total score decrease ≥50% from baseline) was 35% and remission rate (QIDS-SR16 total score ≤5) was 20% after four infusions. Infusions were generally well tolerated with treatment-emergent hypomania observed in only three patients (4.5%) with zero cases of mania or psychosis.

CONCLUSIONS

Real-world effectiveness of IV ketamine for bipolar depression was observed. Repeated doses were associated with greater symptom reduction and adequate tolerability.

Ketamine as a therapeutic agent in major depressive disorder and posttraumatic stress disorder: Potential medicinal and deleterious effects

Major depressive disorder (MDD) and posttraumatic stress disorder (PTSD) are the most common causes of emotional distress that impair an individual's quality of life. MDD is a chronic mental illness that affects 300 million people across the world. Clinical manifestations of MDD include fatigue, loss of interest in routine tasks, psychomotor agitation, impaired ability to focus, suicidal ideation, hypersomnolence, altered psychosocial functioning, and appetite loss. Individuals with depression also demonstrate a reduced behavioral response while experiencing pleasure, a symptom known as anhedonia. Like MDD, PTSD is a prevalent and debilitating psychiatric disorder resulting from a traumatic incident such as sexual assault, war, severe accident, or natural disaster. Symptoms such as recalling event phases, hypervigilance, irritability, and anhedonia are common in PTSD. Both MDD and PTSD pose enormous socioeconomic burdens across the globe. The search for effective treatment with minimal side effects is still ongoing. Ketamine is known for its anesthetic and analgesic properties. Psychedelic and psychotropic effects of ketamine have been found on the nervous system, which highlights its toxicity. In this article, the effectiveness of ketamine as a potential therapeutic for PTSD and MDD along with its mechanisms of action, clinical trials, and possible side effects have been discussed.

The Pharmacokinetics of Ketamine in the Breast Milk of Lactating Women: Quantification of Ketamine and Metabolites

Ketamine is a general anesthetic with over 50 years of safe administration that is in increasing use for psychiatric indications. This is evidenced by the recent FDA approval of intranasal esketamine (the S-enantiomer) for the treatment of depression. With respect to ketamine and lactation, incredibly there are no available data on the secretion of ketamine or its metabolites in human breast milk. This information is essential to guide the use of ketamine in breastfeeding women who suffer with postpartum emotional disorders, ongoing depression, PTSD, and more. To address this unmet need, we conducted a pharmacokinetic analysis of the presence of ketamine and several of its major metabolites (norketamine, dehydronorketamine, and hydroxynorketamine isomers) in four women receiving two different intramuscular doses of ketamine - 0.5 mg/kg and 1.0 mg/kg. Our results demonstrate low and rapidly declining levels of ketamine and metabolites in breast milk during the 12-hour post-dosing period. The mean relative infant dose (RID) obtained from AUC estimates for the 0.5 and 1.0 mg/kg doses were 0.650% and 0.766%, respectively. This provides the foundation for studying the use of ketamine during the post-partum period.

Registered clinical trials investigating treatment of long COVID: a scoping review and recommendations for research

Background

A considerable proportion of individuals report persistent, debilitating and disparate symptoms despite resolution of acute COVID-19 infection (i.e. long COVID). Numerous registered clinical trials investigating treatment of long COVID are expected to be completed in 2021–2022. The aim of this review is to provide a scope of the candidate treatments for long COVID. A synthesis of ongoing long COVID clinical trials can inform methodologic approaches for future studies and identify key research vistas.

Methods

Scoping searches were conducted on multiple national and international clinical trial registries. Interventional trials testing treatments for long COVID were selected. The search timeline was from database inception to 28 July 2021.

Results

This scoping review included 59 clinical trial registration records from 22 countries with a total projected enrolment of 6718. Considerable heterogeneity was exhibited amongst component records with respect to the characterization of long COVID (i.e. name, symptoms- including frequency, intensity, trajectory and duration- mode of ascertainment, and definition of acute phase). In addition, the majority of proposed interventions were non-pharmacological and either targeted multiple long COVID symptoms simultaneously, or focussed on treatment of respiratory/pulmonary sequelae. Multiple interventions targeted inflammation, as well as tissue oxygenation and cellular recovery, and several interventions were repurposed from analogous conditions.

Conclusions

The results of this scoping review investigating ongoing clinical trials testing candidate treatments for long COVID suggest that a greater degree of definitional stringency and homogeneity is needed insofar as the characterization of long COVID and inclusion/exclusion criteria.

Ketamine as a Novel Psychopharmacotherapy for Eating Disorders: Evidence and Future Directions

Eating disorders (EDs) are serious, life-threatening psychiatric conditions associated with physical and psychosocial impairment, as well as high morbidity and mortality. Given the chronic refractory nature of EDs and the paucity of evidence-based treatments, there is a pressing need to identify novel approaches for this population. The noncompetitive N-methyl-D-aspartate receptor (NMDAr) antagonist, ketamine, has recently been approved for treatment-resistant depression, exerting rapid and robust antidepressant effects. It is now being investigated for several new indications, including obsessive–compulsive, post-traumatic, and substance use disorder, and shows transdiagnostic potential for EDs, particularly among clinical nonresponders. Hence, the aim of this review is to examine contemporary findings on the treatment of EDs with ketamine, whether used as a primary, adjunctive, or combination psychopharmacotherapy. Avenues for future research are also discussed. Overall, results are encouraging and point to therapeutic value; however, are limited to case series and reports on anorexia nervosa. Further empirical research is thus needed to explore ketamine efficacy across ED subgroups, establish safety profiles and optimize dosing, and develop theory-driven, targeted treatment strategies at the individual patient level.

Ketamine for psychotic depression: An overview of the glutamatergic system and ketamine's mechanisms associated with antidepressant and psychotomimetic effects

Approximately 0.35-1% of the general population is afflicted with psychotic depression at some time in their life. Psychotic depression is a subtype of major depressive disorder characterized by mood congruent hallucinations and/or delusions. Patients with psychotic depression often represent the most severe cases, with high relapse and mortality rate. Although treatment guidelines recommend a combination of antidepressants and antipsychotics or electroconvulsive therapy, most patients subsequently relapse due to treatment resistance. Furthermore, with the concern of antipsychotic drug's side effects (e.g., tardive dyskinesia), there is a need for an alternative pharmacotherapy for psychotic depression. Recently, several case studies demonstrated that treatment with ketamine not only ameliorated mood, but also improved psychotic symptoms in patients with treatment-resistant depression and psychotic features. However, the safety of ketamine in these patients is controversial since ketamine is known to induce psychotomimetic and dissociative effects. Additionally, the efficacy and safety of ketamine in patients with psychotic depression has not been established as most clinical trials have excluded these persons due to the theorized risk of aggravating psychotic symptoms. Notwithstanding, it is not established empirically that ketamine treatment in psychotic depression would predictably amplify psychotic symptoms and/or overall illness presentation. Future trials evaluating ketamine in depression should include patients with psychotic features to inform whether ketamine is safe and effective in this subpopulation.

Registered clinical studies investigating psychedelic drugs for psychiatric disorders

Psychedelics are a hallucinogenic class of psychoactive drugs with the primary effect of activating non-ordinary states of consciousness. Due to the positive preliminary findings of these drugs in the treatment of psychiatric disorders, the number of registered clinical studies has risen significantly. In this paper, clinical studies registered on clinicaltrials.gov that evaluate the treatment of any psychiatric disorder with psychedelics (excluding ketamine) are summarized and analyzed. 70 registered studies were identified from a clinicaltrials.gov search on December 3, 2020. The majority of studies aim to investigate methylenedioxymethamphetamine (MDMA) (45.7%) and psilocybin (41.4%). Studies evaluating ayahuasca, lysergic acid diethylamide (LSD), ibogaine hydrochloride, salvia divinorum, 5-MeO-DMT and DMT fumarate were less common at 1.4%, 4.2%, 2.8%, 1.4%, 1.4% and 1.4% of total registered studies, respectively. Most of the studies on MDMA, psilocybin, ayahuasca and salvia divinorum investigated their therapeutic effect on post-traumatic stress disorder (PTSD) and major depressive disorder (MDD). LSD was investigated for MDD, anxiety, and severe somatic disorders and ibogaine hydrochloride was investigated for substance and alcohol use disorders. 5-MeO-DMT and DMT fumarate were both investigated for MDD. Only 21/70 registered studies had published results with the majority not yet completed. In view of the large number of ongoing studies investigating psychedelics, it is imperative that these studies are considered by researchers and stakeholders in deciding the most relevant research priorities for future proposed studies.

Therapeutic Potentials of Ketamine and Esketamine in Obsessive-Compulsive Disorder (OCD), Substance Use Disorders (SUD) and Eating Disorders (ED): A Review of the Current Literature

The obsessive-compulsive spectrum refers to disorders drawn from several diagnostic categories that share core features related to obsessive-compulsive disorder (OCD), such as obsessive thoughts, compulsive behaviors and anxiety. Disorders that include these features can be grouped according to the focus of the symptoms, e.g., bodily preoccupation (i.e., eating disorders, ED) or impulse control (i.e., substance use disorders, SUD), and they exhibit intriguing similarities in phenomenology, etiology, pathophysiology, patient characteristics and clinical outcomes. The non-competitive N-methyl-D-aspartate receptor (NMDAr) antagonist ketamine has been indicated to produce remarkable results in patients with treatment-resistant depression, post-traumatic stress disorder and OCD in dozens of small studies accrued over the past decade, and it appears to be promising in the treatment of SUD and ED. However, despite many small studies, solid evidence for the benefits of its use in the treatment of OCD spectrum and addiction is still lacking. Thus, the aim of this perspective article is to examine the potential for ketamine and esketamine in treating OCD, ED and SUD, which all involve recurring and intrusive thoughts and generate associated compulsive behavior. A comprehensive and updated overview of the literature regarding the pharmacological mechanisms of action of both ketamine and esketamine, as well as their therapeutic advantages over current treatments, are provided in this paper. An electronic search was performed, including all papers published up to April 2021, using the following keywords ("ketamine" or "esketamine") AND ("obsessive" OR "compulsive" OR "OCD" OR "SUD" OR "substance use disorder" OR "addiction" OR "craving" OR "eating" OR "anorexia") NOT review NOT animal NOT "in vitro", on the PubMed, Cochrane Library and Web of Science online databases. The review was conducted in accordance with preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. The use and efficacy of ketamine in SUD, ED and OCD is supported by glutamatergic neurotransmission dysregulation, which plays an important role in these conditions. Ketamine's use is increasing, and preliminary data are optimistic. Further studies are needed in order to better clarify the many unknowns related to the use of both ketamine and esketamine in SUD, ED and OCD, and to understand their long-term effectiveness.

Validation of the McIntyre And Rosenblat Rapid Response Scale (MARRRS) in Adults with Treatment-Resistant Depression Receiving Intravenous Ketamine Treatment

BACKGROUND

Depression severity and efficacy measurement scales employed for rapid-acting treatments (e.g., ketamine) were initially validated in adults receiving conventional monoamine-based antidepressants. The emergence of rapid-acting antidepressants in psychiatry provides the impetus for outcome measures that have been validated as sensitive to change with rapid-acting treatments. Herein, we provide results validating the McIntyre and Rosenblat Rapid Response Scale (MARRRS).

METHODS

Adults with treatment-resistant depression (TRD) receiving intravenous (IV) ketamine had depressive symptoms measured with the 16-Item Quick Inventory Depressive Symptoms Self-Report (QIDS-SR-16) and MARRRS at baseline and as a repeated measure across an acute course of four infusions. The MARRRS is a self-report measure assessing depressive symptoms during the past 72 hours.

RESULTS

Sixty-four patients (M_age = 45.4 ± 13.5) were included. The MARRRS had a high internal consistency across acute infusions as determined by Cronbach's alpha (0.84 to 0.94). There was significant convergent validity between the QIDS-SR-16 and MARRRS total scores across infusions (rs(292) = .87, p < .001); the MARRRS was also sensitive to change (rs(49) = .70, p < .001). Exploratory factor analysis revealed that MARRRS items loaded onto two factors (i.e., dysphoria and psychic anxiety) accounting for 63.4% of the total variance.

LIMITATIONS

Heterogenous sample of adults with TRD receiving open-label treatment without placebo comparison.

CONCLUSION

The MARRRS is a brief validated self-report metric of depression symptom severity that is sensitive to change with the rapid-acting antidepressant ketamine. Measuring outcomes with the MARRRS informs treatment progress and facilitates treatment decisions in persons receiving the rapid-acting antidepressant ketamine. Studies of other rapid-acting antidepressants should incorporate outcome measures that are validated as sensitive to change with rapid-acting antidepressants.

Ketamine for post-traumatic stress disorders and it's possible therapeutic mechanism

Posttraumatic stress disorder (PTSD) is a devastating medical illness, for which currently available pharmacotherapies have poor efficacy. Accumulating evidence from clinical and preclinical animal investigations supports that ketamine exhibits a rapid and persistent effect against PTSD, though the underlying molecular mechanism remains to be clarified. In this literature review, we recapitulate the achievements from early ketamine studies to the most up-to-date discoveries, with an effort to discuss an inclusive therapeutic role of ketamine for PTSD treatment and its possible therapeutic mechanism. Ketamine seems to have an inimitable mechanism of action entailing glutamate modulation via actions at the N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors, as well as downstream activation of brain-derived neurotrophic factor (BDNF) and mechanistic target of rapamycin (mTOR) signaling pathways to potentiate synaptic plasticity.

Somatic Comorbidities and Cardiovascular Safety in Ketamine Use for Treatment-Resistant Depression

Background and Objectives: There is evidence for ketamine efficacy in treatment-resistant depression (TRD). Several safety and tolerability concerns arise that some psychotropic agents may provide blood pressure or/and heart rate alterations. The aim of this study is to review blood pressure measurements in course of the treatment with ketamine on treatment refractory inpatients with somatic comorbidities in the course of MDD and BP. Materials and Methods: The study population of 49 patients comprised MDD and BP subjects treated with ketamine registered in the naturalistic observational protocol of treatment-resistant mood disorders (NCT04226963). Results: The conducted analysis showed that among people suffering from hypertension there is a higher increase in systolic blood pressure (RR) after infusion 2 (p = 0.004) than among people who do not suffer from hypertension. Patients with hypertension have a higher increase in diastolic RR compared to those not suffering from hypertension (p = 0,038). Among the subjects with diabetes mellitus, significant differences occurred for infusions 2 (p = 0.020), 7 (p = 0.020), and 8 (p = 0.035) for heart rate (HR), compared to subjects without diabetes mellitus. A higher increase in diastolic RR was noted in the group of subjects suffering from diabetes mellitus (p = 0.010) compared to those who did not. In the hyperlipidemic patients studied, a significantly greater decrease in HR after infusion 5 (p = 0.031) and systolic RR after infusion 4 (p = 0.036) was noted compared to nonpatients. People after a stroke had significantly higher increases in diastolic RR after infusions 4 (p = 0.021) and 6 (p = 0.001) than those who did not have a stroke. Patients suffering from epilepsy had a significantly greater decrease in systolic RR after the 8th infusion (p = 0.017) compared to those without epilepsy. Limitations: The study may be underpowered due to the small sample size. The observations apply to inhomogeneous TRD population in a single-site with no blinding and are limited to the acute administration. Conclusions: This study supports evidence for good safety and tolerability profile for short-term IV ketamine use in TRD treatment. However, risk mitigation measures are to be considered in patients with metabolic and cardiovascular comorbidities.

Case Report: Unexpected Remission From Extreme and Enduring Bulimia Nervosa With Repeated Ketamine Assisted Psychotherapy

Background: Bulimia nervosa is a disabling psychiatric disorder that considerably impairs physical health, disrupts psychosocial functioning, and reduces overall quality of life. Despite available treatment, less than half of sufferers achieve recovery and approximately a third become chronically ill. Extreme and enduring cases are particularly resistant to first-line treatment, namely antidepressants and cognitive behavioral therapy, and have the highest rate of premature mortality. Here, we demonstrate that in such cases, repeated sessions of ketamine assisted psychotherapy (KAP) is an effective treatment alternative for improving symptoms. Case Presentation: A 21-year-old woman presented with extreme and enduring bulimia nervosa. She reported recurrent binge-eating and purging by self-induced vomiting 40 episodes per day, which proved refractory to both pharmacological and behavioral treatment at the outpatient, residential, and inpatient level. Provided this, her physician recommended repeated KAP as an exploratory and off-label intervention for her eating disorder. The patient underwent three courses of KAP over 3 months, with each course consisting of six sessions scheduled twice weekly. She showed dramatic reductions in binge-eating and purging following the first course of treatment that continued with the second and third. Complete cessation of behavioral symptoms was achieved 3 months post-treatment. Her remission has sustained for over 1 year to date. Conclusions: To our knowledge, this is the first report of repeated KAP used to treat bulimia nervosa that led to complete and sustained remission, a rare outcome for severe and enduring cases, let alone extreme ones. Additionally, it highlights the degree to which KAP can be tailored at the individual level based on symptom severity and treatment response. While its mechanism of action is unclear, repeated KAP is a promising intervention for bulimia nervosa that warrants future research and clinical practice consideration.

Intravenous Ketamine Infusions in Treatment-Resistant Bipolar Depression: An Open-Label Naturalistic Observational Study

PURPOSE

Bipolar disorder is a chronic and recurrent condition often associated with treatment resistance and suicidality. There is an unmet need for effective treatment in this group of patients. Ketamine has been demonstrated to have antidepressant and antisuicidal properties in unipolar depression. Most of the available studies concern unipolar depression. Here, we present the efficacy and safety of IV ketamine as an add-on treatment in patients with bipolar I and bipolar II depression.

PATIENTS AND METHODS

Thirteen patients with treatment-resistant bipolar depression (TRBD) received eight IV infusions of 0.5 mg/kg ketamine twice a week over four weeks. This is an open-label naturalistic observational study. Ketamine is an add-on treatment. Depressive symptoms were measured with the Montgomery-Asberg Depression Rating Scale (MADRS), and manic symptoms were measured with the Young Mania Rating Scale (YMRS). Psychomimetic symptoms were assessed with the Clinician-Administered Dissociative States Scale (CADSS) and the Brief Psychiatric Rating Scale (BPRS).

RESULTS

The rates of response and remission after the seventh infusion of ketamine were 61.5% and 46.2%, respectively. A significant antisuicidal effect was observed in responders at the 7th infusion. Suicidality was measured with item 10 on the MADRS scale. The average time to respond was between 21.1 and 23.2 days to remission. There was an increase in the CADSS scores during the treatment compared to baseline and follow-up, but no differences between responders and non-responders were observed. No affective switch was observed according to the YMRS scale scores. Ketamine treatment was associated with a transient increase in arterial blood pressure. No serious adverse events, however, were observed.

CONCLUSION

This report presents the preliminary results of IV ketamine effectiveness and safety in treatment-resistant bipolar depression. The findings suggest that it is a feasible, safe and well-tolerated treatment option in this group of patients. There is a definite need for more studies in this field.

Psychedelics in Psychiatry: Neuroplastic, Immunomodulatory, and Neurotransmitter Mechanisms

Mounting evidence suggests safety and efficacy of psychedelic compounds as potential novel therapeutics in psychiatry. Ketamine has been approved by the Food and Drug Administration in a new class of antidepressants, and 3,4-methylenedioxymethamphetamine (MDMA) is undergoing phase III clinical trials for post-traumatic stress disorder. Psilocybin and lysergic acid diethylamide (LSD) are being investigated in several phase II and phase I clinical trials. Hence, the concept of psychedelics as therapeutics may be incorporated into modern society. Here, we discuss the main known neurobiological therapeutic mechanisms of psychedelics, which are thought to be mediated by the effects of these compounds on the serotonergic (via 5-HT_2A and 5-HT_1A receptors) and glutamatergic [via N-methyl-d-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors] systems. We focus on 1) neuroplasticity mediated by the modulation of mammalian target of rapamycin-, brain-derived neurotrophic factor-, and early growth response-related pathways; 2) immunomodulation via effects on the hypothalamic-pituitary-adrenal axis, nuclear factor ĸB, and cytokines such as tumor necrosis factor-α and interleukin 1, 6, and 10 production and release; and 3) modulation of serotonergic, dopaminergic, glutamatergic, GABAergic, and norepinephrinergic receptors, transporters, and turnover systems. We discuss arising concerns and ways to assess potential neurobiological changes, dependence, and immunosuppression. Although larger cohorts are required to corroborate preliminary findings, the results obtained so far are promising and represent a critical opportunity for improvement of pharmacotherapies in psychiatry, an area that has seen limited therapeutic advancement in the last 20 years. Studies are underway that are trying to decouple the psychedelic effects from the therapeutic effects of these compounds. SIGNIFICANCE STATEMENT: Psychedelic compounds are emerging as potential novel therapeutics in psychiatry. However, understanding of molecular mechanisms mediating improvement remains limited. This paper reviews the available evidence concerning the effects of psychedelic compounds on pathways that modulate neuroplasticity, immunity, and neurotransmitter systems. This work aims to be a reference for psychiatrists who may soon be faced with the possibility of prescribing psychedelic compounds as medications, helping them assess which compound(s) and regimen could be most useful for decreasing specific psychiatric symptoms.

Metabolic Risk Factors and Cardiovascular Safety in Ketamine Use for Treatment Resistant Depression

INTRODUCTION

Ketamine exhibits antidepressant properties in treatment-resistant depression (TRD) with some concern over its cardiovascular safety and tolerability issues. This paper reports on the cardiovascular safety in short-term intravenous ketamine treatment in TRD inpatients with major depressive disorder (MDD) and bipolar disorder (BP).

MATERIALS AND METHODS

The observational study population comprises 35 MDD and 14 BP subjects treated with intravenous ketamine.

RESULTS

Blood pressure (RR) and heart rate (HR) values returned to baseline within 1.5-hours post infusion with no sequelae for all study subjects. Six time points were analyzed for each infusion: 0', 15', 30', 45', 60' and 90' for RR and HR. After the infusion significant peaks in systolic (p = 0.004) and diastolic (p = 0.038) RR were seen. In concomitant medication with selective serotonin reuptake inhibitors (SSRIs), higher RR peaks (p = 0.020; p = 0.048) were seen as compared to other subjects. The decrease in HR was greater (p = 0.02) in the absence of concomitant medication with mood stabilizers as compared to subjects receiving mood stabilizing medication accompanied by the observation of a greater decrease in diastolic RR among those taking mood stabilizers (p = 0.009).

LIMITATIONS

The study may be underpowered due to the small sample size. The observations apply to an inhomogeneous TRD population in a single-site, pilot study, with no blinding and are limited to the acute administration.

CONCLUSION

The study demonstrates good safety and tolerability profile of intravenous ketamine as add-on intervention to current psychotropic medication in TRD, regardless of the MDD or BP type of mood disorders. The abatement of elevated RR and BP scores was observed in time with no sequelae nor harm. Still, cardiovascular risks appear to be more pronounced in subjects with comorbid arterial hypertension and diabetes mellitus.

Ketamine in Bipolar Disorder: A Review

Bipolar disorder (BD) is a psychiatric illness associated with high morbidity, mortality and suicide rate. It has neuroprogressive course and a high rate of treatment resistance. Hence, there is an unquestionable need for new BD treatment strategies. Ketamine appears to have rapid antidepressive and antisuicidal effects. Since most of the available studies concern unipolar depression, here we present a novel insight arguing that ketamine might be a promising treatment for bipolar disorder.