Comparison of Fluvoxamine and Fluoxetine on Clinical and Inflammatory Markers in Patients with Obsessive-Compulsive Disorder: A 12-Week Randomised Study

Background: Obsessive–compulsive disorder (OCD) involves serotonin dysregulation, neurobiological, and inflammatory alterations. While fluvoxamine and fluoxetine are standard selective serotonin reuptake inhibitors (SSRIs), comparative data on biomarkers and early response prediction are limited. Aims: To compare fluvoxamine and fluoxetine in reducing clinical severity, brain-derived neurotrophic factor (BDNF), malondialdehyde (MDA), and inflammatory markers (C-reactive protein [CRP], erythrocyte sedimentation rate [ESR], and procalcitonin [PCT]) over 12 weeks in drug-naïve OCD patients and evaluate whether a 4-week response predicts 12-week outcomes. Materials and Methods: Sixty drug-naïve OCD patients (aged 18–55, ICD-11 criteria), without comorbid depression or anxiety, were randomized to fluvoxamine or fluoxetine. Yale–brown obsessive–compulsive scale (Y-BOCS) scores were recorded at baseline and biweekly up to week 12. World Health Organization Quality of Life-brief version and biomarkers were assessed at baseline, week 4, and week 12. Early and final responses were defined as ≥ 20% and ≥ 35% Y-BOCS reduction, respectively. Results: At 4 weeks, 60% showed early response, predicting 12-week outcomes (sensitivity 83.7% and specificity 53.3%). By week 12, 71.7% had significant symptom reduction. Both SSRIs reduced BDNF ( P < 0.01); fluvoxamine lowered MDA more ( P < 0.011). CRP fell to 1.25 mg/dL (fluvoxamine) and 2.23 mg/dL (fluoxetine); ESR to ~18 mm/hr; PCT to 0.01 ng/mL. Quality of life (QoL) improved significantly, and biomarker changes correlated with clinical improvement. Conclusion: In drug-naïve OCD patients, both SSRIs improved symptoms and QoL over 12 weeks, with early clinical response predicting long-term outcomes. Biomarker changes supported their role in monitoring treatment progress.