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Repeated intranasal esketamine augmentation in treatment-resistant obsessive-compulsive disorder with comorbid major depressive disorder: a prospective case series.

Sergi López-rodríguez, Cinto Segalàs, Eva Real, Mikel Urretavizcaya, Sara Bertolín, José Manuel Menchón

BMC Psychiatry April 26, 2026 DOI: 10.1186/s12888-026-08119-5 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Case series Case report Peer reviewed
Sample size 8
Population Adults with treatment-resistant obsessive-compulsive disorder and comorbid major depressive disorder
Intervention Intranasal esketamine
Dose 56–84 mg/session
Duration 12-week intervention
Topics Depression Esketamine
Keywords Comorbidity Intranasal esketamine Obsessive–compulsive disorder Treatment-resistant Augmentation
Key findings Intranasal esketamine substantially improved depressive symptoms and modestly reduced obsessive-compulsive symptoms in patients with treatment-resistant OCD and comorbid MDD.

Abstract

Background: Patients with obsessive–compulsive disorder (OCD) and comorbid major depressive disorder (MDD) represent a severe subgroup with increased treatment resistance, greater functional impairment, and limited therapeutic options. Intranasal esketamine is a rapidly acting treatment for resistant depression, with emerging interest in potential anti-obsessional effects. However, prospective data in this comorbid population remain lacking.

Methods: We present eight adult cases (mean age 47.3 ± 8.8 years) with treatment-resistant OCD (TR-OCD) and comorbid MDD treated at Bellvitge University Hospital. All patients had failed at least two adequate SSRI trials, clomipramine, cognitive-behavioral therapy with exposure and response prevention, and at least one pharmacological augmentation strategy. Intranasal esketamine (56–84 mg/session) was administered according to the standard antidepressant protocol over 12 weeks. Response was defined as ≥ 35% reduction in Y-BOCS and ≥ 50% reduction in MADRS.

Results: Depressive symptoms improved substantially, with MADRS scores decreasing by 48.8% at Week 12 (p = 0.0026). Obsessive-compulsive symptoms showed a more modest and heterogeneous reduction, with a 30.3% decrease in Y-BOCS scores (p = 0.0037). Four of the eight participants (50.0%) achieved depression response, including two (25.0%) remissions, and four of the eight participants (50.0%) met OCD response criteria. Depressive symptoms improved earlier, whereas OCD symptoms followed a slower and more variable trajectory.

Conclusions: Repeated intranasal esketamine may offer a therapeutic window for patients with severe TR-OCD and comorbid MDD. These preliminary findings support further controlled studies to clarify its role, optimal administration, and integration with psychotherapy.

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