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Radboud M Marijnissen

Department of Psychiatry, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.

2 papers in the library · 2 citations · publishing 2025-2026

Papers

Single fixed-dose intranasal racemic ketamine treatment for the treatment of acute suicidality in a transdiagnostic patient population: Results of a pilot study.

Psychiatry research March 1, 2026 Gijsbrecht H J Roelandt, Jurriaan F M Strous, Radboud M Marijnissen et al. 1 citation

A single open-label dose of 75 mg intranasal racemic ketamine was tested in 12 acutely suicidal patients in an emergency setting, regardless of underlying diagnosis. The treatment was generally feasible, well-tolerated, and safe. Scores for suicidal ideation and depression showed a downward trend one day after treatment, but this effect declined by day seven. One patient developed ketamine misuse several weeks after participation. No definitive conclusions about efficacy could be drawn from this pilot study.

The Ketamine Trial for Acute Suicidality (KETA): Study Protocol of a Double-Blind Randomized Placebo-Controlled Superiority Trial on Intranasal Racemic Ketamine Compared to the Active Placebo Intranasal Midazolam as Treatment for Acute Suicidality.

International journal of methods in psychiatric research December 1, 2025 Jurriaan F M Strous, Gijs H J Roelandt, Jens H van Dalfsen et al. 1 citation

A single 75 mg intranasal dose of ketamine reduces acute suicidal thoughts more than a 4 mg dose of the active placebo midazolam, measured 180 minutes after administration. The double-blind randomized trial includes 100 patients presenting with acute suicidality regardless of psychiatric diagnosis. The primary outcome is the change in suicidal ideation using the Beck Scale for Suicide Ideation. Secondary outcomes assess depression severity, tolerability, and biological markers. The study design addresses patient selection, ketamine formulation, clinical management, and follow-up timing.