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Joshua D Rosenblat

Poul Hansen Family Centre for Depression, Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, Ontario, Canada; Institute of Medical Science, University of Toronto, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada. Electronic address: joshua.rosenblat@uhn.ca.

34 papers in the library · 629 citations · publishing 0-2026

Papers

Engaging Mood Brain Circuits with Psilocybin (EMBRACE): a study protocol for a randomized, placebo-controlled and delayed-start, neuroimaging trial in depression.

Trials July 3, 2024 Joshua M Poulin, Gregory E Bigford, Krista L Lanctôt et al. 3 citations

A proposed randomized controlled trial will test whether a single 25 mg dose of psilocybin, compared to a placebo, acutely alters cerebral blood flow and functional brain activity in mood-regulating networks in people with major depressive disorder or persistent depressive disorder. Fifty participants from a mood disorders clinic will be randomly assigned to receive either psilocybin or a placebo, with the placebo group later crossing over to receive psilocybin. The study will use arterial spin labelling and blood oxygenation level-dependent functional MRI to measure brain changes intraday and at three weeks. Clinical outcomes will be tracked with the Montgomery-Åsberg Depression Rating Scale and other scales. The work aims to clarify psilocybin's neuroplastic mechanisms and identify early brain-based predictors of treatment response.

A Global Population-Based Study on the Association Between Ketamine and Esketamine With Suicidality Using WHO VigiBase.

The Journal of clinical psychiatry July 7, 2025 Angela T H Kwan, Moiz Lakhani, Joshua D Rosenblat et al. 2 citations

In a global pharmacovigilance analysis of adverse event reports from the World Health Organization's VigiBase database, esketamine was associated with higher reporting odds for suicidal ideation compared to lithium (5.13 times) and fluoxetine (3.34 times), while ketamine showed lower reporting odds for suicidal ideation, suicide attempt, and completed suicide relative to both reference drugs. Both drugs had lower reporting odds for suicide attempts and completed suicides. The authors caution that causality cannot be determined from these observational data.

Psychedelics as a potential treatment for borderline personality disorder: A narrative review.

Psychiatry research July 1, 2026 Erin Artna, Guneet Sandhu, Noah Chisamore et al. 1 citation

Borderline personality disorder (BPD) is a serious mental illness with limited treatment options. Although patients with BPD are often excluded from psychedelic research due to safety concerns about suicide and substance misuse, emerging evidence suggests psychedelics may target core BPD symptoms and common co-occurring mood and anxiety disorders. This narrative review analyzed 22 studies from multiple databases examining ketamine, esketamine, and psilocybin in individuals with BPD. Preliminary evidence indicates these psychedelics may be safe and effective for improving core BPD symptoms and socio-occupational functioning, but more high-quality research focused on BPD-specific outcomes is needed to clarify their potential as a treatment modality.

Comparing Antidepressant Effects of Psilocybin-Assisted Psychotherapy in Individuals That Were Unmedicated at Initial Screening Versus Individuals Discontinuing Medications for Study Participation: Comparaison des effets antidépresseurs de la psychothérapie assistée par la psilocybine (PAP) chez les personnes non médicamentées à la sélection initiale et les personnes ayant arrêté les médicaments pour participer à l’étude

The Canadian Journal of Psychiatry March 25, 2025 Noah Chisamore, Erica S Kaczmarek, Zoe Doyle et al. 1 citation

A single 25 mg dose of psilocybin combined with psychotherapy produced clinically significant reductions in depression, anxiety, and suicidality symptoms over two months in people with treatment-resistant depression. Among 27 participants, those who tapered off antidepressant medications before treatment (n = 18) and those not on antidepressants at screening (n = 9) showed comparable improvements, with no significant differences between groups on clinician-rated depression, self-reported depression, anxiety, or suicidality. The intensity of the psychedelic experience was also similar. These results suggest that tapering antidepressants before psilocybin-assisted psychotherapy may not diminish therapeutic benefits, though further research is needed.

Intranasal Ketamine for Existential Distress in Advanced Cancer.

Journal of pain and symptom management August 1, 2026 Stefan Aguiar, Mary Makarious, Orly Lipsitz et al.

In adults with advanced cancer receiving palliative care, intranasal ketamine was associated with clinically meaningful improvements in existential distress, anxiety, symptom burden, and quality of life. Fifteen participants who completed three doses of ketamine showed improvements exceeding established minimal clinically important differences on measures of anxiety, death and dying distress, overall symptoms, and quality of life. Improvements in existential well-being were larger than those in physical symptoms. Changes in depression did not significantly correlate with changes in existential distress outcomes, suggesting ketamine may have independent effects on multiple dimensions of distress in this population.

Evaluating the abuse liability of ketamine in the treatment of mood disorders: A systematic review.

Journal of psychopharmacology (Oxford, England) June 24, 2026 Shreya Vasudeva, Gabrielle F M Lovell, Sabrina Wong et al.

Ketamine and its enantiomer esketamine show low risk of abuse, dependence, or misuse when administered under controlled clinical supervision, based on a systematic review of 30 studies (25 clinical and 5 preclinical). Clinical studies found minimal evidence of craving, dose escalation, or illicit use in monitored settings. Preclinical work indicated that (S)-ketamine produces reward-related behaviors, racemic ketamine shows reinforcing effects at higher doses, and (R)-ketamine has minimal reinforcing effects. Abuse risk was identified mainly in case reports lacking proper monitoring. The findings support safe incorporation of ketamine into mood disorder treatment protocols with structured administration and ongoing monitoring.

Progress, potential and pitfalls of ketamine as a treatment for depression

Expert Opinion on Pharmacotherapy January 22, 2026 Diana Orsini, Sara D Di Luch, Gabrielle F. M. Lovell et al.

A large body of evidence from clinical trials and real-world studies supports the antidepressant effects of intravenous ketamine and intranasal esketamine. Larger studies have provided reassuring safety data, including for long-term treatment. Alternative routes of administration show promise for scalability, but their efficacy relative to intravenous ketamine remains unclear. Preliminary data suggest ketamine may also be effective for bipolar disorders, personality disorders, posttraumatic stress, and obsessive-compulsive disorder. Further research is needed to optimize protocols, such as combining ketamine with other interventions. Challenges include functional unblinding, expectancy-related bias, and treatment costs.

Evaluating the potential risk of ketamine-induced hepatotoxicity in the treatment of mood and anxiety disorders: A systematic review.

General hospital psychiatry January 1, 2026 Gabrielle F M Lovell, Shreya Vasudeva, Diana K Orsini et al.

Ketamine, an anesthetic also used for mood and anxiety disorders, may cause mild, temporary elevations in liver enzymes, but serious liver damage appears rare. A systematic review of 13 studies (5 randomized trials, 3 observational studies, and 5 case reports) involving 1,017 patients—mostly with major depressive disorder or bipolar disorder—found 75 mild liver enzyme elevations across trials, with only a few cases of impaired liver function. No cases met Hy's Law criteria for severe drug-induced liver injury. Case reports described more severe liver issues that improved with dose reduction or stopping treatment. Routine liver monitoring during ketamine treatment remains advisable.

Examining the impact of comorbid posttraumatic stress disorder on ketamine's real-world effectiveness in treatment-resistant depression.

European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology February 1, 2025 Danica E Johnson, Nelson B Rodrigues, Sydney Weisz et al.

Depression with co-occurring posttraumatic stress disorder (PTSD) leads to more severe symptoms and poorer response to standard treatments. In a retrospective analysis of 134 patients with treatment-resistant depression, four ketamine infusions (0.5-0.75 mg/kg) reduced depressive symptoms equally in those with and without comorbid PTSD; no significant group-by-time interaction was found. PTSD symptoms also significantly improved across all symptom clusters, with moderate to large effect sizes. Ketamine shows promise as an effective intervention for this hard-to-treat population, though future randomized trials should explore factors driving improvement and long-term outcomes.