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Roger S McIntyre

University of Toronto, University Health Network

130 papers in the library · 4,810 citations · publishing 0-2026

Papers

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Hallucinogen persisting perceptual disorder: a scoping review covering frequency, risk factors, prevention, and treatment

Expert Opinion on Drug Safety April 15, 2022 Marcus A. Doyle, Susan Ling, Leanna M.W. Lui et al. 24 citations

INTRODUCTION: Hallucinogen persisting perception disorder (HPPD) affects a subset of persons who use hallucinogens and is defined as the repeated experience of hallucinations and other perceptual disturbances as a result of prior intoxications. As select hallucinogens are under development for the treatment of selectmental disorders, there is a need to better characterize this disorder. AREAS...

The efficacy and safety of adjunctive intranasal esketamine treatment in major depressive disorder: a systematic review and meta-analysis

Expert Opinion on Drug Safety April 6, 2022 Muhammad Youshay Jawad, Joshua D. Di Vincenzo, Felicia Ceban et al. 29 citations

INTRODUCTION: Intranasal (IN) esketamine represents an innovative treatment for individuals with treatment resistant depression and depression with suicidal ideation and behavior. Herein, we synthesize extant long-term studies (≥ 4 weeks) regarding this treatment. RESEARCH DESIGN AND METHODS: The interventional studies of IN esketamine in patients with depression having a study period of at...

Intravenous ketamine for depression: A clinical discussion reconsidering best practices in acute hypertension management.

Frontiers in Psychiatry 2022 Ryan Yip, Jennifer Swainson, Atul Khullar et al. 13 citations

Ketamine is a versatile medication with an emerging role for the treatment of numerous psychiatric conditions, including treatment resistant depression. Current psychiatry guidelines for its intravenous administration to treat depression recommend regular blood pressure monitoring and an aggressive approach to potential transient hypertensive episodes induced by ketamine infusions. While this...

Frequency analysis of symptomatic worsening following ketamine infusions for treatment resistant depression in a real-world sample: Results from the canadian rapid treatment center of excellence.

Psychiatry Research 2022 Joshua D. Di Vincenzo, Orly Lipsitz, Nelson B Rodrigues et al. 11 citations

Antidepressants are associated with symptomatic worsening in a subgroup of patients. Replicated evidence has demonstrated rapid and robust antidepressant effects with intravenous (IV) ketamine in treatment resistant depression (TRD); however, the risk of ketamine worsening depressive symptoms in a subgroup of patients remains unknown. Herein we report a retrospective analysis on the rates of...

Molecular Mechanisms of Psilocybin and Implications for the Treatment of Depression

CNS Drugs November 17, 2021 Susan Ling, Felicia Ceban, Leanna M.W. Lui et al. 123 citations

Therapeutic deficiencies with monoaminergic antidepressants invites the need to identify and develop novel rapid-acting antidepressants. Hitherto, ketamine and esketamine are identified as safe, well-tolerated rapid-acting antidepressants in adults with treatment-resistant depression, and also mitigate measures of suicidality. Psilocybin is a naturally occurring psychoactive alkaloid and...

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

Psychiatry Research October 1, 2021 Tuyen T. Le, Joshua D. Di Vincenzo, Kayla M Teopiz et al. 26 citations

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...

Registered clinical studies investigating psychedelic drugs for psychiatric disorders.

Journal of Psychiatric Research July 1, 2021 Ashley N. Siegel, Shakila Meshkat, Katie Benitah et al. 101 citations

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...

Do sleep changes mediate the anti‐depressive and anti‐suicidal response of intravenous ketamine in treatment‐resistant depression?

Journal of Sleep Research June 16, 2021 Nelson B Rodrigues, Roger S McIntyre, Orly Lipsitz et al. 28 citations

Summary 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...

Strategies to Prolong Ketamine’s Efficacy in Adults with Treatment-Resistant Depression

Advances in Therapy April 30, 2021 Eric P. Mcmullen, Yena Lee, Orly Lipsitz et al.

Ketamine treatment is capable of significant and rapid symptom improvement in adults with treatment-resistant depression (TRD). A limitation of ketamine treatment in TRD is the relatively short duration of time to relapse (e.g., median 2–4 weeks). The objective of the systematic review herein is to identify strategies capable of prolonging the acute efficacy of ketamine in adults with TRD....

Synthesizing the Evidence for Ketamine and Esketamine in Treatment-Resistant Depression: An International Expert Opinion on the Available Evidence and Implementation

American Journal of Psychiatry March 17, 2021 Roger S McIntyre, Joshua D. Rosenblat, Charles B. Nemeroff et al. 694 citations

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...

The effectiveness, safety and tolerability of ketamine for depression in adolescents and older adults: A systematic review.

Journal of Psychiatric Research March 1, 2021 Joshua D. Di Vincenzo, Ashley N. Siegel, Orly Lipsitz et al. 59 citations

The majority of antidepressant medication trials have focused on adult populations (ages 18-65), with much less research in older and younger populations. Moreover, key differences in the efficacy and safety of antidepressants have been identified between these age groups. Ketamine has emerged as a promising new treatment for treatment resistant depression (TRD). The objective of this review is...

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

Journal of Affective Disorders March 1, 2021 Roger S McIntyre, Nelson B Rodrigues, Orly Lipsitz et al. 10 citations

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,...

Efficacy of dextromethorphan for the treatment of depression: a systematic review of preclinical and clinical trials

Expert Opinion on Emerging Drugs January 2, 2021 Amna Majeed, Jiaqi Xiong, Kayla M Teopiz et al. 48 citations

INTRODUCTION: The large percentage of adults with major depressive disorder (MDD) insufficiently responding and/or tolerating conventional monoamine-based antidepressants invites the need for mechanistically novel treatments. Convergent evidence implicates glutamatergic signaling as a potential therapeutic target in MDD. AREAS COVERED: The synthesis herein of preclinical and clinical studies...

A simplified 6-Item clinician administered dissociative symptom scale (CADSS-6) for monitoring dissociative effects of sub-anesthetic ketamine infusions.

Journal of Affective Disorders December 29, 2020 Nelson B Rodrigues, Roger S McIntyre, Orly Lipsitz et al.

BACKGROUND 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. METHODS Retrospective data of 260 patients with treatment-resistant depression (TRD) receiving IV...

The acute antisuicidal effects of single-dose intravenous ketamine and intranasal esketamine in individuals with major depression and bipolar disorders: A systematic review and meta-analysis.

Journal of Psychiatric Research December 11, 2020 Jiaqi Xiong, Orly Lipsitz, David C J Chen-Li et al. 122 citations

The efficacy of ketamine in reducing suicidal ideation (SI) has been previously reported. We aimed to evaluate acute anti-SI effects of single-dose ketamine in different formulations/routes of administration by pooling results from randomized controlled trials (RCTs). A systematic search was conducted on Cochrane, Embase, Medline, and PubMed from inception to July 1st, 2020. Studies were...

Effectiveness of intravenous ketamine in mood disorder patients with a history of neurostimulation

CNS Spectrums December 10, 2020 Nelson B Rodrigues, Ashley N. Siegel, Orly Lipsitz et al. 17 citations

BACKGROUND: Patients 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. METHODS: This retrospective, posthoc...

Does body mass index predict response to intravenous ketamine treatment in adults with major depressive and bipolar disorder? Results from the Canadian Rapid Treatment Center of Excellence

CNS Spectrums December 3, 2020 Orly Lipsitz, Roger S McIntyre, Nelson B Rodrigues et al. 25 citations

BACKGROUND: Higher 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). METHODS: Adults (N = 230) with TRD received four infusions of IV ketamine at a community-based clinic. Changes in symptoms...

The Effects of Ketamine on Cognition in Treatment-Resistant Depression: A Systematic Review and Priority Avenues for Future Research.

Neuroscience and Biobehavioral Reviews November 23, 2020 Hartej Gill, Barjot Gill, Nelson B Rodrigues et al. 92 citations

Replicated evidence has documented cognitive deficits in populations with treatment-resistant depression (TRD). Approximately 40% of patients with MDD present with impairment of one or more cognitive domains. As such, there is an unmet need to discover treatments that have pro-cognitive effects in TRD patients. Ketamine has demonstrated efficacy as a rapid-onset intervention for the treatment...

The Canadian Network for Mood and Anxiety Treatments (CANMAT) Task Force Recommendations for the Use of Racemic Ketamine in Adults with Major Depressive Disorder: Recommandations Du Groupe De Travail Du Réseau Canadien Pour Les Traitements De L’humeur Et De L’anxiété (Canmat) Concernant L’utilisation De La Kétamine Racémique Chez Les Adultes Souffrant De Trouble Dépressif Majeur

The Canadian Journal of Psychiatry November 11, 2020 Jennifer Swainson, Alexander McGirr, Pierre Blier et al. 109 citations

OBJECTIVE: -methyl-d-aspartate (NMDA) receptor antagonist, has demonstrated rapid antidepressant effects in patients with TRD. The Canadian Network for Mood and Anxiety Treatments (CANMAT) convened a task force to review the evidence for efficacy and safety of racemic ketamine and to provide recommendations for its use in clinical practice. METHODS: A systematic review was conducted with...

The effect of intravenous, intranasal, and oral ketamine in mood disorders: A meta-analysis.

Journal of Affective Disorders November 1, 2020 Roger S McIntyre, Isabelle P. Carvalho, Leanna M.W. Lui et al. 186 citations

BACKGROUND Ketamine is established as a rapid and effective treatment in adults with treatment-resistant depression (TRD). The availability of different formulations and routes of delivery invites the need for evaluating relative effect sizes. METHODS Effect size with respect to depression symptom reduction for each formulation and route of delivery was compared at discrete time-points (i.e.,...

The effectiveness of intravenous ketamine in adults with treatment-resistant major depressive disorder and bipolar disorder presenting with prominent anxiety: Results from the Canadian Rapid Treatment Center of Excellence

Journal of Psychopharmacology October 11, 2020 Roger S McIntyre, Nelson B Rodrigues, Orly Lipsitz et al. 19 citations

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...

The emerging role of psilocybin and MDMA in the treatment of mental illness

Expert Review of Neurotherapeutics September 21, 2020 Hartej Gill, Barjot Gill, David C J Chen-Li et al. 62 citations

Psychedelics, such as psilocybin and MDMA, offer an alternative avenue of therapy for many mental health disorders. Available evidence indicates that psychedelics may offer a single-dose, rapid effect model that have robust effects with treatment-resistant mental disorders and a unique advantage as a possible monotherapy for mental illness. Novel clinical trials that evaluate the safety,...

Safety and tolerability of IV ketamine in adults with major depressive or bipolar disorder: results from the Canadian rapid treatment center of excellence

Expert Opinion on Drug Safety June 15, 2020 Nelson B Rodrigues, Roger S McIntyre, Orly Lipsitz et al. 50 citations

ABSTRACT Objectives Rigorous clinical trials suggest ketamine is safe and well-tolerated in patients with treatment-resistant depression (TRD). There is a paucity of data on the safety and tolerability of ketamine in community-based clinics treating patients with TRD. Methods Retrospective data was analyzed from 203 patients with TRD who received repeat-dose IV ketamine. Safety was...

The effectiveness of ketamine on anxiety, irritability, and agitation: Implications for treating mixed features in adults with major depressive or bipolar disorder

Bipolar Disorders May 14, 2020 Roger S McIntyre, Orly Lipsitz, Nelson B Rodrigues et al. 64 citations

Abstract 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...

Oral Ketamine for Depression

The Journal of Clinical Psychiatry April 15, 2019 Joshua D. Rosenblat, André F. Carvalho, Madeline Li et al. 111 citations

OBJECTIVE: Intravenous (IV) ketamine has rapid and robust antidepressant effects; however, poor accessibility of the IV route often limits its use. Numerous alternative routes of administration are being investigated. Oral ketamine is particularly appealing for its ease of use with the potential for high accessibility. The objective of the current systematic review, in accordance with PRISMA,...