Abstract Ketamine induces a sequence of temporally distinct effects on brain function, yet its impact on reward processing beyond the acute post-administration phase remains unclear. In this single-blind, placebo-controlled, crossover study, 28 healthy participants received 0.5 mg/kg racemic ketamine or placebo via a 40 min intravenous infusion. Functional magnetic resonance imaging was...
Research SquareJuly 9, 2026Samuel Westenhöfer, Yamina Ehrt, Barbora Provaznikova et al.
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Abstract Background : Treatment-resistant depression (TRD) is associated with substantial clinical and socioeconomic burden. Intranasal esketamine has shown efficacy for TRD in clinical trials and real-world studies. However, evidence on optimal maintenance scheduling is limited. We therefore investigated whether two maintenance schedules differing in their inter-dose intervals were associated...
Ketamine, a well-established antidepressant and dissociative anesthetic, is also used recreationally in the club and chemsex scene. Survey and qualitative data suggest that while ketamine facilitates chemsex encounters, it diminishes the intensity of the sexual experience. To investigate this phenomenon from a neuroscientific perspective while considering ketamine's sex-specific effects. Two...
The N-methyl-D-aspartate receptor antagonist ketamine has found broad application in the field of psychiatry. Due to its rapid antidepressant and anti-suicidal properties, it is used as a treatment for major depressive disorder. Furthermore, ketamine evokes dissociative and psychotropic states, which allows the modeling of schizophrenic symptoms. The thalamus, a main target for ketamine's...
Modern electroconvulsive therapy (ECT) and the approval of nasal esketamine for clinical use have significantly improved the approach to treatment-resistant depression (TRD), which is defined as non-response to at least two different courses of antidepressants with verified adherence to treatment, adequate dosage, and duration of treatment. The goal of this literature review is to present the...
Ketamine exerts rapid antidepressant effects by enhancing neuroplasticity, particularly in the amygdala and hippocampus-regions involved in fear processing and learning. While the role of ketamine's dissociative effects in its antidepressant response is debated, anxiety experienced during infusion has been negatively correlated with treatment outcomes. In this single-blind, placebo-controlled...
Modern electroconvulsive therapy (ECT) and ketamine currently represent the most effective treatment options in depressed patients showing non-response to two or more trials of antidepressants. Recently, large sample head-to-head comparisons of intravenous ketamine versus ECT for treatment-resistant depression (TRD) have fuelled the debate on which therapy might be more effective. However, the...
Introduction Converging evidence suggests that ketamine elicits antidepressant effects via enhanced neuroplasticity precipitated by a surge of glutamate and modulation of GABA. Magnetic resonance spectroscopic imaging (MRSI) illustrates changes to cerebral glutamate and GABA immediately following ketamine administration during dissociation. However, few studies assess subacute changes in the...
Over the last years, a number of studies have been conducted to clarify the neurobiological correlates of ketamine application. However, comprehensive information regarding the influence of ketamine on cortical activity is still lacking. Using resting-state functional MRI and integrating pharmacokinetic information, a double-blind, randomized, placebo-controlled, crossover study was performed...
Clinical trials demonstrated that ketamine exhibits rapid antidepressant efficacy when administered in subanaesthetic dosages. We reviewed currently available literature investigating efficacy, response rates and safety profile. Twelve studies investigating unipolar, seven on bipolar depression were included after search in medline, scopus and web of science. Randomized, placebo-controlled or...