Abstract
Objective: Obsessive–compulsive disorder (OCD) is a chronic and disabling psychiatric disorder characterized by recurrent obsessions and compulsions that significantly impair functioning. Although selective serotonin reuptake inhibitors (SSRIs) and cognitive behavioral therapy (CBT), particularly exposure and response prevention (ERP), remain the cornerstone of treatment, a substantial proportion of patients experience partial response or treatment resistance (TR), leading to increasing interest in augmentation strategies and emerging therapeutic approaches.

Methods: This structured narrative review summarizes pharmacological strategies for OCD, focusing on antidepressant treatment and antipsychotic augmentation, with emphasis on clinical studies published between 2021 and 2025. A structured narrative review was conducted based on studies published between 2021 and 2025 and identified through searches of PubMed/MEDLINE, Scopus, and Web of Science. Studies were categorized under antidepressant treatment and antipsychotic augmentation strategies. Due to heterogeneity in study designs and interventions, a quantitative meta-analysis was not performed, and findings were synthesized according to clinical efficacy, tolerability, and guideline recommendations.

Results: Current evidence supports SSRIs and CBT with ERP as first-line treatments, while clomipramine remains an effective second-line option limited by tolerability concerns. Antipsychotic augmentation, particularly with aripiprazole and risperidone, demonstrates the strongest evidence among pharmacological augmentation strategies. Overall, optimal management of OCD requires an individualized treatment approach integrating symptom severity, comorbidities, treatment tolerability, and patient characteristics.

Conclusion: Future well-designed randomized controlled trials are needed to clarify the efficacy, safety, and clinical positioning of emerging treatment strategies and to guide integrative treatment models combining pharmacological, psychotherapeutic, and neuromodulation approaches.

Key words: Antidepressants, Antipsychotics, Augmentation strategies, Obsessive-compulsive disorder, Treatment-resistant OCD