en Cognitive Neuroscience Cognitive Neuroscience Original Original <div style="text-align: justify;"><strong>Introduction</strong>: This study aimed to compare the efficacy of three common selective serotonin reuptake inhibitors (SSRIs)&mdash;fluoxetine, fluvoxamine, and sertraline&mdash;in treating anxiety disorders, major depressive disorder (MDD), and obsessive-compulsive disorder (OCD).&nbsp;<br> <strong>Methods</strong>: This eight-week randomized controlled clinical trial included 90 participants who were randomly assigned to receive either fluoxetine (20 mg), fluvoxamine (150 mg), or sertraline (100 mg). Symptom severity was assessed at baseline and after treatment using the Beck anxiety inventory (BAI), the Beck depression inventory-II (BDI-II), and the Yale-Brown obsessive compulsive scale (Y-BOCS).&nbsp;<br> <strong>Results</strong>: All three medications significantly reduced symptoms of anxiety, depression, and OCD (P<0.05). However, a one-way ANOVA showed no statistically significant difference among the efficacies of the three drugs in reducing scores on any of the assessment scales.&nbsp;<br> <strong>Conclusion</strong>: While fluoxetine, fluvoxamine, and sertraline were all effective, none demonstrated superior efficacy over the others. The choice of medication should therefore be based on considerations, such as side effect profiles, drug interactions, cost, and patient-specific characteristics.</div> Selective serotonin reuptake inhibitors (SSRIs), Fluoxetine, Obsessive-compulsive disorder (OCD), Fluvoxamine, Sertraline, Depression, Anxiety 337 344 http://bcn.iums.ac.ir/browse.php?a_code=A-10-8104-1&slc_lang=en&sid=1 Mohammad Saeed Maniati saeedmaniati@gmail.com 13700319475328460058693 13700319475328460058693 No Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Reza Khosrowabadi Reza Khosrowabadi 13700319475328460058694 13700319475328460058694 No Institute for Cognitive and Brain Sciences, Shahid Beheshti University, Tehran, Iran. Jamal Shams J_shams@yahoo.com 13700319475328460058695 13700319475328460058695 Yes Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.