Abstract

This clinical research investigates the use of Spravato (esketamine), an NMDA receptor antagonist, in the United Arab Emirates for patients diagnosed with major depressive disorder (MDD) or treatment-resistant depression (TRD) who have not responded adequately to standard antidepressant regimens. The primary focus is on evaluating the clinical effectiveness of esketamine in alleviating depressive symptoms in a real-world clinical setting in Dubai. This represents one of the early structured efforts in the region to document the clinical impact of this novel mechanism-based treatment.

Background

Treatment-resistant depression (TRD) remains a significant clinical challenge affecting a subset of patients who show limited or inadequate response to multiple conventional antidepressant trials. Traditional antidepressants primarily modulate monoaminergic systems (serotonin, norepinephrine, dopamine); however, these approaches fail to achieve remission in approximately 30% of patients with MDD.

Novel agents such as esketamine, which modulate glutamatergic neurotransmission via NMDA receptor antagonism, represent a mechanistically distinct approach. Esketamine has demonstrated efficacy in clinical trials for TRD and has been approved in several countries for this indication. This study is positioned within the context of the UAE's growing adoption of advanced psychiatric treatments and aims to document outcomes in a local clinical environment.

NMDA Receptor Antagonism & Glutamatergic Mechanisms

Esketamine and its active metabolite are non-competitive NMDA receptor antagonists. The mechanism of antidepressant action is proposed to involve:

• NMDA receptor blockade: Reduces excessive glutamatergic tone, particularly in circuits involved in mood regulation and reward processing.
• AMPA receptor potentiation: Following NMDA blockade, there is secondary potentiation of AMPA receptors, which promotes synaptic plasticity and long-term potentiation (LTP).
• Rapid-onset antidepressant effects: Unlike monoaminergic antidepressants (which require weeks to months), NMDA antagonists can produce measurable symptom reduction within hours to days.
• Neural circuit remodeling: Facilitates structural remodeling in prefrontal-limbic circuits implicated in mood, fear extinction, and cognitive flexibility.

Study Objectives

Primary Objective

To determine whether treatment with Spravato (intranasal esketamine) leads to a measurable reduction in depressive symptoms in patients with major depressive disorder or treatment-resistant depression who have not responded adequately to prior antidepressant interventions.

Secondary Objectives

• To observe changes in functional status (work, social, and self-care domains) during the treatment period.
• To assess tolerability and safety profile of esketamine within this population.
• To evaluate overall clinical impression and patient-reported outcomes.
• To document response patterns and identify potential predictors of clinical response.

Methods & Study Design

Framework: This study follows a clinical observational framework in patients receiving Spravato as part of their therapeutic plan in Dubai. The study is non-randomized and non-controlled.

Population: Patients aged 18+ diagnosed with major depressive disorder or treatment-resistant depression (defined as inadequate response to ≥2 adequate antidepressant trials) who are undergoing treatment with Spravato in a clinical setting.

Intervention: Spravato (intranasal esketamine) administered according to clinical protocol and regulatory guidance, typically 2 times weekly initially, with titration as clinically indicated.

Data Collection: Symptom severity is monitored using standardized depression rating scales (such as the Montgomery-Åsberg Depression Rating Scale, MADRS, or patient-reported scales) at baseline and at predefined follow-up intervals between January and March 2026. Additional clinical data include vital signs, patient-reported functional changes, and qualitative clinical observations.

Timeline: Baseline assessment (January 2026) → Interval assessments (weekly or bi-weekly) → End-of-study assessment (March 2026).

Outcome Measures

Primary Outcome

Change in depressive symptom scores from baseline to end of observation (March 2026), as measured by standardized depression rating scales.

Secondary Outcomes

• Response rate: Proportion of patients achieving ≥50% reduction in baseline symptom severity.
• Remission rate: Proportion of patients achieving minimal residual depressive symptoms.
• Functional improvement: Changes in occupational, social, and self-care domains.
• Tolerability: Frequency and severity of adverse events.
• Clinician-rated global improvement: Overall clinical and functional trajectory.

Clinical Significance

This research represents one of the early structured efforts in the UAE to document the clinical impact of esketamine-based treatment in patients with limited response to conventional therapies. The findings are expected to contribute to:

• Better understanding of how advanced pharmacological strategies can be integrated into regional mental health practice.
• Documentation of clinical outcomes in a non-Western clinical context.
• Informing future protocols, larger studies, and translational work in neuropsychopharmacology within the region.
• Highlighting the role of mechanism-based pharmacotherapy in treatment-resistant depression.

Clinical & Methodological Notes

This study is ongoing, and parameters, analyses, weighting, and interpretations are subject to refinement as additional data are collected between January and March 2026. The study does not replace clinical judgment, regulatory guidelines, or institutional protocols. All clinical decisions regarding patient care remain the responsibility of the treating clinician and multidisciplinary team.

Study Status: Active (data collection ongoing as of April 2026).