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Objective .To identify a meaningful change threshold (MCT) in depression outcomes in adults with treatment-resistant major depressive disorder (MDD) or bipolar disorder (BD) receiving intravenous ketamine treatment at a community-based mood disorders center. Method .A triangular approach integrating both anchor-based and distributive methods was used to identify meaningful change on the patient-reported Quick Inventory for Depressive Symptoms Self-Report 16-Item (QIDS-SR16) as associated with the Patient Global Impression - Severity (PGI-S). Both the QIDS-SR16 and the PGI-S are self-report measures, and were collected at five timepoints (timepoints were approximately 2-7 days apart). Results .A total of 297 adults with treatment-resistant depression (TRD) as part of either DSM-5-defined MDD or BD were included. The MCT for the QIDS-SR16 revealed that a mean improvement of 3.38 points from baseline was comparable to a 1-point improvement on the PGI-S. Together with an examination of the probability density function, a 3.5-point change is a reasonable MCT (i.e., 1-point PGI-S improvement) for the QIDS-SR16. A 2-point symptomatic improvement on the QIDS-SR16 was associated with no change on the PGI-S. Conclusion .A 3.5-point reduction in the QIDS-SR16 represents a MCT based on the PGI-S for adults with treatment-resistant MDD or BD receiving intravenous ketamine treatment at a community-based mood disorders center. These findings are limited by the post-hoc nature of this analysis and open-label case-series design. Measurement-based care decisions by patients, providers and clinicians, as well as cost/reimbursement decisions should include consideration of meaningful change along with conventional objective outcomes.

Objective To evaluate the safety, tolerability, and effectiveness of repeated doses of intravenous (IV) ketamine in older adults (i.e., ≥60 years of age) with treatment-resistant depression. Method In this case series, fifty-three older adults (Mage = 67, SD = 6; 57% female [n = 30]) received 4 IV ketamine infusions, administered over 1–2 weeks. Effectiveness of IV ketamine was measured using the Quick Inventory for Depressive Symptomatology–Self Report 16 (QIDS-SR16) approximately 2 days after infusions 1–3, and 1–2 weeks after infusion 4. Safety was measured as hemodynamic changes before, during, immediately after, and 20 minutes after each infusion. Tolerability was assessed via systematic reporting of treatment-emergent adverse events during and after each infusion, in addition to symptoms of dissociation measured using the Clinician Administered Dissociative States Scale. Partial response (25%–50% symptomatic improvement from baseline), response (≥50% symptomatic improvement from baseline), clinically significant improvements (≥25% symptomatic improvement from baseline), and remission rates (QIDS-SR16 ≤5) were also calculated. Results Participants reported significant decreases in depressive symptoms (i.e., as measured by the QIDS-SR16) with repeated ketamine infusions (F(4, 92) = 7.412, p Conclusion Ketamine was associated with transient treatment-emergent hypertension. Response and remission rates were comparable to those reported in general adult samples. Findings are limited by the open-label, chart review nature of this study.

Background The efficacy of monoamine-based antidepressants in adults with major depressive disorder (MDD) is attenuated in persons with greater pre-treatment functional impairment. Herein, we investigated whether pre-treatment functioning in outpatients with treatment-resistant depression (TRD) moderates response to intravenous (IV) ketamine. Methods Adults (N= 326; Mage = 45) with DSM-5-defined MDD or bipolar disorder and TRD received repeat-dose IV ketamine at a community-based clinic. Function was evaluated with the Sheehan Disability Scale (SDS), using total scores as well as scores on the subdomains of workplace/school, social life, and family life/home responsibilities. The primary dependent measure was change in depressive symptoms from pre-treatment to post-infusion 4, as measured by the Quick Inventory for Depressive Symptomatology-Self Report-16. Results Total functional disability, as well as the subdomains of social life and family life/home responsibilities, significantly moderated response to IV ketamine (p = .003; p = .008; p = .008). Follow-up simple slopes analyses indicated a significant improvement in depressive symptoms across the functional domain spectrum (ps mean functional impairment within the sample) was associated with a greater change in depressive symptoms. Workplace function did not significantly moderate response to IV ketamine (p = .307), suggesting that individuals with significantly impaired workplace functioning may expect a similar response to ketamine as those with less workplace impairment. Conclusions Symptomatic benefit with IV ketamine was observed in patients with TRD and significant pre-treatment functional impairment. The foregoing result has implications for mechanism of action, cost-effectiveness, and patient selection in adults with TRD receiving IV ketamine.

The emerging roles of ketamine and esketamine as effective rapid-acting antidepressants hold promise for patients suffering from treatment-resistant depression and/or major depressive disorder with suicidality. Practitioner familiarity with common tolerability/safety concerns along with pragmatic prevention and management strategies are needed to reduce patient burden and improve the acceptability and accessibility of these treatments. The most common treatment-emergent adverse events associated with ketamine/esketamine are dissociation, anxiety, nausea, increased blood pressure, and headache. The majority of side effects are mild, transient, dose dependent, and attenuate with subsequent treatments. Patient selection, baseline physical and psychiatric assessments, and an appropriate setting are critical first steps in the prevention and mitigation of adverse events. Patient education and supportive interventions play central roles in the prevention and management of select adverse events. Severe and/or clinically significant adverse effects may necessitate the judicious use of adjunctive medications. Moreover, practitioners must remain vigilant to the potential for abuse liability and long-term adverse events, for which there are insufficient data. This article succinctly reviews common treatment-emergent adverse events of ketamine and esketamine within the context of mood disorders, and provides practical suggestions for prevention and management at point-of-care.

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 (Mage = 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 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.

Replicated international studies have underscored the human and societal costs associated with major depressive disorder. Despite the proven efficacy of monoamine-based antidepressants in major depression, the majority of treated individuals fail to achieve full syndromal and functional recovery with the index and subsequent pharmacological treatments. Ketamine and esketamine represent pharmacologically novel treatment avenues for adults with treatment-resistant depression. In addition to providing hope to affected persons, these agents represent the first non-monoaminergic agents with proven rapid-onset efficacy in major depressive disorder. Nevertheless, concerns remain about the safety and tolerability of ketamine and esketamine in mood disorders. Moreover, there is uncertainty about the appropriate position of these agents in treatment algorithms, their comparative effectiveness, and the appropriate setting, infrastructure, and personnel required for their competent and safe implementation. In this article, an international group of mood disorder experts provides a synthesis of the literature with respect to the efficacy, safety, and tolerability of ketamine and esketamine in adults with treatment-resistant depression. The authors also provide guidance for the implementation of these agents in clinical practice, with particular attention to practice parameters at point of care. Areas of consensus and future research vistas are discussed.

Dissociation is a treatment-emergent adverse event commonly associated with IV ketamine, often measured using the 23-item Clinician-Administered Dissociative States Scale (CADSS). The objective of this study was to develop a short form version of the CADSS for easier clinical use.Retrospective data of 260 patients with treatment-resistant depression (TRD) receiving IV ketamine were randomly divided into two datasets. The first dataset (n = 130) was leveraged to develop a brief 6-item version of the CADSS (CADSS-6) based on items most sensitive to ketamine-induced dissociation. The CADSS-6 questions were then applied to the second dataset (n = 130) and the Spearman's correlation between the full-length CADSS and the CADSS-6 were assessed.The CADSS-6 was developed from questions 1, 2, 6, 7, 15, and 22 from the full length CADSS. There was a strong significant correlation between the CADSS-6 total score and the CADSS total score at infusions 1 (rs(106) = 0.92, p0.001), 2 (rs(100) = 0.91, p0.001), 3(rs(99) = 0.95, p0.001) and 4 (rs(102) = 0.94, p0.001).The CADSS-6 was developed using a retrospective data; therefore, the scale remains unvalidated in this population.The CADSS-6 presented herein was sensitive to dissociation experienced by patients receiving IV ketamine. Overall, the CADSS-6 was strongly correlated at each infusion with the full-length CADSS. While future studies should look to validate the CADSS-6 in a TRD sample, this scale offers clinicians a brief assessment that can be used to characterize symptoms of dissociation.

Intravenous (IV) ketamine has been shown to have rapid and robust antidepressant effects in adults with treatment-resistant depression (TRD). Urological toxicity has been observed in chronic ketamine abusers as evidenced by dysuria, urgency, and hematuria. The foregoing observation provides the basis for evaluating whether ketamine-induced urological toxicity (KIUT) is associated with sub-anesthetic doses of ketamine (0.5-1.0 mg/kg) in adults with mood disorders. The overarching objective of this article is to identify potential mechanisms of KIUT which appears to be dose and frequency dependent. Available research indicates that high-frequency ketamine is associated with disruption of the urothelial barrier as well as direct ketamine toxicity (i.e., decreased expression of junction proteins) in KIUT of the bladder. Chronic and high-frequency ketamine use is also associated with bladder inflammation mediated via neurogenic and IgE inflammation. Other non-mutually exclusive causes are nerve hyperplasia, hypersensitivity, cell apoptosis, microvascular damage, and overexpression of carcinogenic genes. Notwithstanding the evidence of KIUT in ketamine abusers, there is no evidence that ketamine and/or esketamine treatment in adults with mood disorders is associated with KIUT. However, all patients receiving ketamine/esketamine for mood disorder treatment should be queried about genitourinary symptoms during acute and, where applicable, maintenance dosing.

BackgroundHigher body mass index (BMI) has been found to predict greater antidepressant response to intravenous (IV) ketamine treatment. We evaluated the association between BMI and response to repeat-dose IV ketamine in patients with treatment-resistant depression (TRD).MethodsAdults (N = 230) with TRD received four infusions of IV ketamine at a community-based clinic. Changes in symptoms of depression (ie, Quick Inventory for Depressive Symptomatology-Self-Report 16; QIDS-SR16), suicidal ideation (SI; ie, QIDS-SR16 SI item), anxiety (ie, Generalized Anxiety Disorder-7 Scale), anhedonic severity (ie, Snaith–Hamilton Pleasure Scale), and functioning (ie, Sheehan Disability Scale) following infusions were evaluated. Participants were stratified by BMI as normal (18.0-24.9 kg/m2; n = 72), overweight (25-29.9 kg/m2; n = 76), obese I (30-34.9 kg/m2; n = 47), or obese II (≥35.0 kg/m2; n = 35).ResultsSimilar antidepressant effects with repeat-dose ketamine were reported between BMI groups (P = .261). In addition, categorical partial response (P = .149), response (P = .526), and remission (P = .232) rates were similar between the four BMI groups.ConclusionsThe findings are limited by the observational, open-label design of this retrospective analysis. Pretreatment BMI did not predict response to IV ketamine, which was effective regardless of BMI.

Background: Ketamine is an emerging treatment for treatment-resistant depression (TRD) associated with rapid and robust improvements in depressive symptoms and suicidality. However, the efficacy and safety of ketamine in transitional age youth (TAY; age 18–25) populations remains understudied. Methods: In this retrospective analysis, TAY patients ( n = 52) receiving ketamine for TRD were matched for sex, primary diagnosis, baseline depression severity, and treatment resistance with a general adult (GA) sample (age 30–60). Patients received four ketamine infusions over 2 weeks (0.5–0.75 mg/kg over 40 min). The primary outcome was the change in Quick Inventory of Depressive Symptomatology Self-Report 16-item (QIDS-SR16) over time. Secondary outcomes were changes in QIDS-SR16 suicidal ideation (SI) item, anxiety (Generalized Anxiety Disorder 7-item (GAD-7)), and adverse effects (ClinicalTrials.gov: NCT04209296). Results: A significant main effect of infusions on reduction of total QIDS-SR16 ( p Conclusion: Ketamine was associated with comparable clinical benefits, safety, and tolerability in a TAY sample as compared to a matched GA TRD sample.

The emerging roles of ketamine and esketamine as effective rapid-acting antidepressants hold promise for patients suffering from treatment-resistant depression and/or major depressive disorder with suicidality. Practitioner familiarity with common tolerability/safety concerns along with pragmatic prevention and management strategies are needed to reduce patient burden and improve the acceptability and accessibility of these treatments. The most common treatment-emergent adverse events associated with ketamine/esketamine are dissociation, anxiety, nausea, increased blood pressure, and headache. The majority of side effects are mild, transient, dose dependent, and attenuate with subsequent treatments. Patient selection, baseline physical and psychiatric assessments, and an appropriate setting are critical first steps in the prevention and mitigation of adverse events. Patient education and supportive interventions play central roles in the prevention and management of select adverse events. Severe and/or clinically significant adverse effects may necessitate the judicious use of adjunctive medications. Moreover, practitioners must remain vigilant to the potential for abuse liability and long-term adverse events, for which there are insufficient data. This article succinctly reviews common treatment-emergent adverse events of ketamine and esketamine within the context of mood disorders, and provides practical suggestions for prevention and management at point-of-care.

A proportion of individuals with major depressive disorder (MDD) do not receive adequate therapeutic benefit from conventional monoaminergic antidepressant drugs, leading to treatment-resistant depression (TRD). Ketamine has been shown to provide rapid and significant efficacy in treating patients with TRD. The majority of published studies have investigated the adjunctive efficacy of ketamine with one or more monoaminergic antidepressants. There remains a clinical need to ascertain the relative effectiveness of ketamine monotherapy versus adjunctive ketamine treatment in adults with TRD. In this retrospective study, we investigate multidimensional, self-reported outcomes (i.e., antidepressant, anti-suicidality, antianxiety, and anti-functional impairment) of 220 patients to compare monotherapy (n = 39) and adjunctive (n = 181) ketamine treatment for TRD at a community-based clinic. Both groups had clinically and statistically significant antidepressant effects (p 0.05). Individuals receiving ketamine monotherapy exhibited a significantly greater reduction on the suicidal ideation (SI) item of the Quick Inventory for Depressive Symptomatology-Self Report 16-Item (QIDS-SR

Herein we evaluate the impact of COVID-19 restrictions on antidepressant effectiveness of intravenous (IV) ketamine in adults with treatment-resistant depression (TRD). We conducted a case series analysis of adults with TRD (n = 267) who received four ketamine infusions at an outpatient clinic in Ontario, Canada, during COVID-19 restrictions (from March 2020 - February 2021; n = 107), compared to patients who received treatment in the previous year (March 2019 - February 2020; n = 160). Both groups experienced significant and comparable improvements in depressive symptoms, suicidal ideation, and anxiety with repeated ketamine infusions. Effectiveness of IV ketamine was not attenuated during the COVID-19 period.

Sleep disturbances are commonly reported in patients with treatment-resistant depression (TRD). Available data have shown that intravenous (IV) ketamine is an effective treatment for patients with TRD and growing data suggest ketamine may improve overall sleep architecture. In the present study, we evaluated whether changes in sleep symptoms mediated the anti-depressive and/or anti-suicidal effects of IV ketamine and whether improvement in sleep correlated with a higher likelihood of achieving response or remission. Adults with TRD received four infusions of IV ketamine at a community-based clinic. Total depressive symptom severity was measured with the Quick Inventory Depressive Symptoms Self-Report 16-Item (QIDS-SR16 ) at baseline and was repeated across four infusions. Suicidal ideation (SI) and four sleep symptoms were measured using the SI item and the five sleep items on the QIDS-SR16 . A total of 323 patients with TRD received IV ketamine. Self-reported improvements in insomnia, night-time restlessness, hypersomnia, early morning waking, and total sleep were significant partial mediators to the improvements observed in depression severity. Similarly, insomnia, night-time restlessness, early morning waking and total sleep improvements mediated the reduction of IV ketamine on SI. All sleep items, except for hypersomnia, were associated with an increased likelihood of achieving response or remission. Notably, each point improvement in total sleep score was significantly associated with achieving responder/remitter status (odds ratio 3.29, 95% confidence interval 2.00-5.41). Insomnia, sleep restlessness, early morning waking and total sleep improvements were significant mediators of antidepressant and anti-suicidal improvements in patients with TRD receiving IV ketamine.

BackgroundPatients unsuccessfully treated by neurostimulation may represent a highly intractable subgroup of depression. While the efficacy of intravenous (IV) ketamine has been established in patients with treatment-resistant depression (TRD), there is an interest to evaluate its effectiveness in a subpopulation with a history of neurostimulation.MethodsThis retrospective, posthoc analysis compared the effects of four infusions of IV ketamine in 135 (x̄ = 44 ± 15.4 years of age) neurostimulation-naïve patients to 103 (x̄ = 47 ± 13.9 years of age) patients with a history of neurostimulation. The primary outcome evaluated changes in depression severity, measured by the Quick Inventory for Depression Symptomatology-Self Report 16-Item (QIDS-SR16). Secondary outcomes evaluated suicidal ideation (SI), anxiety severity, measured by the Generalized Anxiety Disorder 7-Item (GAD-7), and consummatory anhedonia, measured by the Snaith–Hamilton Pleasure Scale (SHAPS).ResultsFollowing four infusions, both cohorts reported a significant reduction in QIDS-SR16 Total Score (F (4, 648) = 73.4, P < .001), SI (F (4, 642) = 28.6, P < .001), GAD-7 (F (2, 265) = 53.8, P < .001), and SHAPS (F (2, 302) = 45.9, P < .001). No between-group differences emerged. Overall, the neurostimulation-naïve group had a mean reduction in QIDS-SR16 Total Score of 6.4 (standard deviation [SD] = 5.3), whereas the history of neurostimulation patients reported a 4.3 (SD = 5.3) point reduction.ConclusionIV ketamine was effective in reducing symptoms of depression, SI, anxiety, and anhedonia in both cohorts in this large, well-characterized community-based sample of adults with TRD.

Background: Individuals meeting criteria for treatment-resistant depression (TRD) are differentially affected by high levels of anxiety symptoms. Aims: There is a need to identify the efficacy of novel rapid-onset treatments in adults with mood disorders and comorbid anxious-distress. Methods: This study included patients with treatment-resistant major depressive disorder (MDD) or bipolar disorder (BD) who were receiving intravenous (IV) ketamine treatment at a community-based clinic.Anxious-distress was proxied using items from the Quick Inventory of Depressive Symptomatology–Self Report 16-item (QIDS-SR16) and Generalized Anxiety Disorder 7-item (GAD7) scales. The difference in QIDS-SR16 total score, QIDS-SR16 suicidal ideation (SI) item and GAD7 score were analyzed between groups. Results: A total of 209 adults with MDD ( n = 177) and BD ( n = 26) were included in this analysis. From this sample, 94 patients (mean = 45 ± 13.9 years) met the criteria for anxious-distress. Individuals meeting the criteria for anxious-distress exhibited a significantly greater reduction in QIDS-SR16 total score following four infusions ( p = 0.02) when compared with patients not meeting the anxious-distress criteria. Both anxious-distressed and low-anxiety patients exhibited a significant reduction in SI ( p < 0.0001) following four infusions.Finally, there was a significantly greater reduction in anxiety symptoms in the anxious-distress group compared with the non–anxious distress group following three ( p = 0.02) and four infusions ( p < 0.001). Conclusion: Patients with TRD and prominent anxiety receiving IV ketamine exhibited a significant reduction in depressive, SI and anxiety symptoms.

Intravenous (IV) ketamine has been shown to have rapid and robust antidepressant effects in adults with treatment-resistant depression (TRD). Urological toxicity has been observed in chronic ketamine abusers as evidenced by dysuria, urgency, and hematuria. The foregoing observation provides the basis for evaluating whether ketamine-induced urological toxicity (KIUT) is associated with sub-anesthetic doses of ketamine (0.5-1.0 mg/kg) in adults with mood disorders. The overarching objective of this article is to identify potential mechanisms of KIUT which appears to be dose and frequency dependent. Available research indicates that high-frequency ketamine is associated with disruption of the urothelial barrier as well as direct ketamine toxicity (i.e., decreased expression of junction proteins) in KIUT of the bladder. Chronic and high-frequency ketamine use is also associated with bladder inflammation mediated via neurogenic and IgE inflammation. Other non-mutually exclusive causes are nerve hyperplasia, hypersensitivity, cell apoptosis, microvascular damage, and overexpression of carcinogenic genes. Notwithstanding the evidence of KIUT in ketamine abusers, there is no evidence that ketamine and/or esketamine treatment in adults with mood disorders is associated with KIUT. However, all patients receiving ketamine/esketamine for mood disorder treatment should be queried about genitourinary symptoms during acute and, where applicable, maintenance dosing.

OBJECTIVE To determine the effectiveness of intravenous (IV) ketamine on anxiety, irritability, agitation, and suicidality, in adults with treatment-resistant major depressive disorder (MDD) or bipolar disorder (BD). METHOD Adults (N = 201) with treatment-resistant MDD or BD received repeat-dose IV ketamine treatment at a community-based clinic. Mixed features were measured using symptoms of anxiety, irritability, and agitation (AIA), as measured by the Generalized Anxiety Disorder-7 (GAD-7) scale. The Quick Inventory for Depressive Symptomatology Self-Report-16 (QIDS-SR16 ) was used to measure overall treatment response, and the QIDS-SR16 suicidal ideation (SI) item was used to measure change in SI symptoms with ketamine treatment. The anxiety, irritability, and agitation items on the GAD-7 were used to assess effectiveness of IV ketamine in treating symptoms of mixed features. RESULTS In this retrospective analysis, 113 participants met AIA criteria. Participants with AIA experienced a significantly greater reduction in overall depressive symptoms (F(1, 558) = 9.49, P = .002), SI (F(1, 558) = 3.103, P = .079), anxiety (F(1, 198) = 5.52, P = .007), irritability (F(1, 198) = 28.35, P

Women are disproportionately represented amongst samples of adults with treatment-resistant depression (TRD). Ketamine has demonstrated rapid and robust efficacy in adults with TRD. Herein, we sought to determine whether the effectiveness of intravenous (IV) ketamine was influenced by menopausal status in women with TRD. We defined premenopausal women as those under the age of 45 (n = 52), while postmenopausal women (n = 54) were those over the age of 51. Participants received four IV ketamine infusions over one-to-two weeks at a community-based center for adults with TRD. The primary outcome of interest was the change in depressive symptom severity as measured by the Quick Inventory of Depressive Symptomatology Self-Report 16 (QIDS-SR16) following four infusions, compared to pretreatment. The secondary outcomes were improvements in suicidal ideation (SI; i.e., QIDS-SR16 SI item), anxiety (i.e., Generalized Anxiety Disorder-7 scale), anhedonic severity (i.e., Snaith-Hamilton Pleasure Scale), and workplace and psychosocial function (i.e., Sheehan Disability Scale). Menopausal status did not influence overall treatment response, F (4, 280) = 1.83, p = .123, ηp2 = 0.025. Both premenopausal and postmenopausal participants demonstrated similar response rates (30% and 26%, respectively) and remission rates (both 13%) to IV ketamine treatment following four infusions. Premenopausal women experienced improvements in social function more rapidly than postmenopausal women, F (2, 174) = 1.65, p = .047, ηp2 = 0.019. Postmenopausal women experienced reduction in SI more rapidly than premenopausal women, F (4, 280) = 2.72, p = .030, ηp2 = 0.037. These preliminary post-hoc findings provide the impetus for future studies to investigate the moderational role of menopausal status, as defined by hormone levels, on response to IV ketamine for TRD.

Anhedonia is a trans-diagnostic, multidimensional phenotype that mediates patient outcomes and suicidality. Convergent evidence suggests that ketamine may be effective in targeting measures of anhedonia in adults with treatment resistant depression (TRD).This retrospective, post-hoc analysis included 203 (x̄ = 45 ± 14.6 years of age) patients receiving four infusions of intravenous (IV) ketamine at a community-based clinic. The primary outcome measure was change in anhedonia severity, as measured by the Snaith-Hamilton Pleasure Scale (SHAPS). Secondary measures sought to determine if improvement on the SHAPS mediated the effect of repeated IV ketamine infusions on symptoms of depression and suicidal ideations, as measured by the Quick Inventory for Depression Symptomatology-Self Report 16-Item (QIDS-SRAfter adjusting for age, sex, primary diagnosis, concomitant medication, body mass index, and baseline depression severity, there was a statistically significant reduction in symptoms of anhedonia with IV ketamine treatment (F (2, 235.6) = 31.6, p0.001). Improvements in depressive symptoms, suicidal ideation, and anxiety symptoms with repeated-dose IV ketamine were significantly partially mediated by reduction in anhedonic severity. Moreover, the combination of number of infusions received and change in anhedonic severity accounted for 26% of the variance in depressive score improvements.This is a post-hoc analysis of retrospective data and lacks a control group.Ketamine was effective in improving measures of anhedonia in this large, well-characterized community-based sample of adults with TRD. Improvements in anhedonia also partially mediated the significant improvement in depressive symptoms, suicidality, and anxiety.

Major depressive disorder (MDD) is a debilitating disorder with increasing prevalence globally. Despite the development of novel treatments for MDD, many patients present with treatment resistant depression (TRD), identified by treatment non-response following one or more adequate trials of an antidepressant. Rapastinel may prove to be a viable treatment for TRD; it has the potential to produce a rapid antidepressant response without serious adverse events and improve functional symptoms. Areas covered: We review the efficacy of rapastinel via completed and on-going clinical trials. The online databases Pubmed, clinicaltrials.gov and clinicaltrialsregister.eu were searched for rapastinel (GLYX-13) treatment in subjects with MDD. Nine clinical trials were identified. Expert opinion: Rapastinel is a novel and potentially transformative treatment for individuals with TRD. There is a limited number of clinical studies so far, but this compound has the potential to provide rapid, reliable and robust antidepressant effects without psychotomimetic and other unwanted side effects. Alternative formulations such as the oral formulation, provide the opportunity for rapastinel to be administered less frequently, i.e. once weekly. Furthermore, the beneficial effects on measures of cognition and suicidality so far, represent a tremendous advantage.

Background The effectiveness, tolerability, and safety of intravenous (IV) ketamine in adults with treatment resistant depression (TRD) receiving care in real-word settings is insufficiently characterized. Herein, results from a naturalistic, retrospective study are presented from a Canadian outpatient IV ketamine clinic. Methods Adults (N = 213; Mage = 45) with Major Depressive Disorder or Bipolar Disorder, with a minimum of Stage 2 antidepressant resistance, received IV ketamine at a community-based multi-disciplinary clinic. The primary outcome measure was change from baseline to post-infusion 4 on the Quick Inventory for Depression Symptomatology-Self Report-16 (QIDS-SR16; n = 190). Secondary measures included QIDS-SR16-measured response and remission rates, changes from baseline to endpoint in Generalized Anxiety Disorder-7 Scale (GAD-7; n = 188) and the Sheehan Disability Scale (SDS; n = 168). Results Significant improvement in total depressive symptoms severity (p Limitations This was a naturalistic, retrospective study, without a control group. Conclusions IV ketamine was safe, well-tolerated, and effective at improving depressive, anxiety, and functional impairment symptoms in a well-characterized cohort of adults with TRD.

Ketamine may exert pro-cognitive effects on select measures of cognition in adults with mood disorders. We evaluated the effectiveness of intravenous (IV) ketamine on cognition in 68 adult outpatients with treatment-resistant depression (TRD) at the Canadian Rapid Treatment Center of Excellence between July 3, 2018 and April 16, 2020 (NCT04209296). Eligibility criteria for the present retrospective study included: primary diagnosis of major depressive or bipolar disorder; currently depressed; and insufficient response to two or more prior treatments. Participants received four infusions of ketamine hydrochloride (0.5-0.75 mg/kg) over 1-2 weeks. We assessed objective and subjective measures of cognition before and after two infusions, i.e., Digit Symbol Substitution Test (DSST), Trail Making Test-B (TMT-B), Patient Deficits Questionnaire, 5-item (PDQ-5-D). Ketamine significantly improved DSST (effect size [ES]=0.60), TMT-B (ES=0.84), as well as PDQ-5-D scores (ES=0.63), indicative of a moderate-to-large effect size. Improvements in DSST and PDQ-5-D with ketamine were mediated by reductions in depressive symptoms, whereas improvements in TMT-B were independent of changes in depressive symptoms. Our results support the independent, rapid-onset, pro-cognitive effects with IV ketamine in adults with TRD. Larger, randomized, controlled trials with ketamine wherein cognition is the primary outcome measure in mood and non-mood disorder samples are warranted.

Numerous clinical trials have reported that intravenous (IV) ketamine demonstrates rapid antidepressant and anti-suicidal effects in patients with treatment-resistant depression (TRD). These studies, however, have not characterized whether these antidepressant effects translate to improvements in workplace productivity and functionality. Adults with TRD received repeated doses of IV ketamine at a community-based clinic (n = 171). We evaluated patient outcomes at two timepoints of interest: (1) acute-phase (i.e., following 4–6 infusions, 17.6 ± 12.6 days from baseline) and (2) maintenance-phase (i.e., following 7–10 infusions, 153.9 ± 63.4 days from baseline). The primary outcome measure was change from baseline to maintenance-phase scores on the Sheehan Disability Scale (SDS) workplace/school item as well as days underproductive (i.e., presenteeism) and days lost (i.e., absenteeism). Secondary measures included the Quick Inventory for Depression Symptomatology-Self Report 16-Item (QIDS-SR16). There was a significant reduction in workplace/school disability, and significantly reduced symptoms of presenteeism and absenteeism. At the acute-phase outcome, this translated to 2 more days of productivity and 1.5 less days absent from work. Additionally, IV ketamine exhibited a sustained antidepressant effect across the ten infusions. IV ketamine was associated with a significant reduction in workplace/school disability and demonstrated improvements in symptoms of presenteeism and absenteeism.

Background Early symptomatic improvement with monoamine-based antidepressants is predictive of treatment response. The objective of this study was to determine if early symptomatic improvements with intravenous (IV) ketamine predicted treatment response to an acute course of four infusions. Method 134 adults with treatment resistant depression (TRD) received four ketamine infusions over one to two weeks. Depressive symptoms were measured using the Quick Inventory for Depressive Symptomatology Self-Report16 (QIDS-SR16) at baseline and post-infusions 1, 2, 3, and 4. Early improvement was defined as ≥20% reduction in QIDS-SR16 scores after the first or second infusion. Linear models were used to determine whether early improvement was associated with post-infusion 4 QIDS-SR16 scores after controlling for baseline characteristics. Results Early improvement post-infusion 1 (β = −3.52, 95% BCa CI [−5.40, −1.78]) and 2 (β = −3.16, 95% BCa CI [−5.75, −1.59]) both significantly predicted QIDS-SR16 scores post-infusion 4. Early improvers had significantly lower QIDS-SR16 scores at post-infusion 4 (post-infusion 1 improvers: M = 9.8, SD = 4.5; post-infusion 2 improvers: M = 10.6, SD = 5.7) compared to non-early improvers (post-infusion 1 non-improvers: M = 13.7, SD = 5.8; post-infusion 2 non-improvers: M = 14.1, SD = 5.3) when controlling for baseline characteristics. The majority (58%) of individuals who did not improve post-infusions 1 or 2 still experienced an antidepressant response or partial response (≥20% reduction in QIDS-SR16) post-infusion 4. Limitations This is a post-hoc analysis of an open-label study. Conclusion Early improvement was associated with greater antidepressant effects following a course of four ketamine infusions. However, individuals who did not show early improvements still had a high likelihood of experiencing clinically significant symptom reduction after the fourth infusion, suggesting that completing four infusions, regardless of early symptom changes, is appropriate and merited.