Obsessive-compulsive disorder and bipolar disorder comorbidity: Diagnostic challenges, clinical implications and therapeutic strategies

Background: Bipolar disorder frequently presents with psychiatric comorbidities, among which obsessive-compulsive disorder (OCD) poses significant diagnostic and therapeutic challenges. The concurrent presentation of these disorders complicates treatment strategies, particularly given the risk of antidepressant-induced mood destabilization. Objective: To examine the clinical presentation, diagnostic complexities, and therapeutic management of OCD-bipolar disorder comorbidity through a case report and comprehensive literature review. Methods: We present a detailed case of a 37-year-old female with OCD-bipolar disorder comorbidity, initially misdiagnosed and subsequently treated with multiple pharmacological interventions. A systematic review of the literature was conducted using PubMed, PsycINFO, and Cochrane databases. Results: The patient exhibited an 8-year delay in bipolar disorder diagnosis following initial OCD presentation. Multiple SSRI trials without mood stabilization precipitated subsyndromal hypomanic episodes. Eventual treatment with quetiapine 600 mg/day achieved dual symptom control. Literature review reveals OCD-bipolar comorbidity prevalence of 6-16%, with increased suicide risk, treatment resistance, and diagnostic complexity. Conclusions: OCD-bipolar comorbidity represents a distinct clinical entity requiring early recognition and specialized treatment approaches. Atypical antipsychotics, particularly quetiapine, demonstrate efficacy for dual symptom control. Clinicians should maintain high suspicion for underlying bipolarity in treatment-resistant OCD cases.