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Robin L. Okada

4 papers in the library · 123 citations · publishing 2023-2025

Papers

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Opioids diminish the placebo antidepressant response: Observational post hoc findings from a randomized controlled ketamine trial.

Journal of Affective Disorders July 15, 2025 Theresa R. Lii, Josephine R. Flohr, Robin L. Okada et al. 1 citation

The endogenous opioid system is thought to play a role in the placebo antidepressant response. A recent trial comparing the rapid antidepressant effects of ketamine versus placebo in surgical patients, some of whom were on chronic opioid therapy, revealed a substantial placebo effect. This finding provided an opportunity to test the hypothesis that opioid agonist exposure interacts with placebo...

DOI: 10.1016/j.jad.2025.04.008 (opens in new tab) Full text (opens in new tab) Opioids Depression treatment Opioid effects Placebo response +2

Opioids Diminish the Placebo Antidepressant Response: A Post Hoc Analysis of a Randomized Controlled Ketamine Trial.

medRxiv November 2, 2024 Theresa R. Lii, Josephine R. Flohr, Robin L. Okada et al. preprint

The endogenous opioid system is thought to play a role in the placebo antidepressant response. A recent trial comparing the rapid antidepressant effects of ketamine versus placebo in surgical patients, some of whom were on chronic opioid therapy, revealed a substantial placebo effect. This finding provided an opportunity to test the hypothesis that opioid agonist exposure interacts with placebo...

DOI: 10.1101/2024.09.24.24314243 (opens in new tab) Full text (opens in new tab) Depression/mental health/mood disorders Opioids/painkillers/narcotics Placebo effect/placebo response Psychopharmacology/drug interactions +1

Randomized trial of ketamine masked by surgical anesthesia in patients with depression

Nature Mental Health October 19, 2023 Theresa R. Lii, Ashleigh E. Smith, Josephine R. Flohr et al. 94 citations

Ketamine may have antidepressant properties, but its acute psychoactive effects complicate successful masking in placebo-controlled trials. Here we present a single-center, parallel-arm, triple-masked, randomized, placebo-controlled trial assessing the antidepressant efficacy of intravenous ketamine masked by surgical anesthesia (ClinicalTrials.gov, NCT03861988). Adult patients (N = 40) with...

Randomized Trial of Ketamine Masked by Surgical Anesthesia in Depressed Patients

medRxiv Preprint Server April 28, 2023 Theresa R. Lii, Ashleigh E. Smith, Josephine R. Flohr et al. 28 citations preprint

Abstract BACKGROUND Ketamine may have antidepressant properties, but its acute psychoactive effects complicate successful masking in placebo-controlled trials. METHODS In a triple-masked, randomized, placebo-controlled trial, 40 adult patients with major depressive disorder were randomized to a single infusion of ketamine (0.5 mg/kg) or placebo (saline) during anesthesia as usual for routine...

DOI: 10.1101/2023.04.28.23289210 (opens in new tab) Full text (opens in new tab) Mood improvement Psychiatric medication Mental health intervention Therapeutic approach +11