en Clinical Neuroscience Clinical Neuroscience Original Original <div style="text-align: justify;"><strong>Introduction</strong>: Antioxidants prevent the progression of neuropsychiatric disorders, such as bipolar disorder (BD). Omega-3 fatty acid supplementation helps prevent lipid peroxidation and improve antioxidant status. This study aims to investigate the effect of omega-3 supplementation on serum levels of antioxidant status in patients with BD.&nbsp;<br> <strong>Methods</strong>: In this study, 28 patients with BD received an omega-3 fatty acid supplement (2 g/daily) while the other 28 patients received edible paraffin oil (2 g/daily) for 60 days. The activities of superoxide dismutase (SOD), catalase (CAT), and total antioxidant capacity (TAC) were evaluated in pre-intervention and post-intervention.&nbsp;<br> <strong>Results</strong>: The results showed that omega-3 supplementation increased the activities of SOD (12.94&plusmn;3.84 U/mL vs 17.72&plusmn;3.59 U/mL) and CAT (5.08&plusmn;1.61 nmol/min/mL vs 6.43&plusmn;1.33 nmol/min/mL) in post-intervention compared to pre-intervention (P=0.001). The results also showed that omega-3 supplementation increased the activities of SOD (17.72&plusmn;3.59 U/mL vs 13.79&plusmn;3.12 U/mL) and CAT (6.43&plusmn;1.33 nmol/min/mL vs 4.89&plusmn;1.45 nmol/min/mL) compared to the control group in post-intervention (P=0.001). Omega-3 supplementation did not have significant effects on the serum concentration of TAC compared to pre-intervention (P=0.373) and control group (P=0.604).&nbsp;<br> <strong>Conclusion</strong>: Omega-3 supplementation increased the activities of SOD and CAT and may decrease the progression of disease via increasing antioxidant status.</div> Antioxidant capacity, Bipolar disease, Catalase, Omega-3 109 116 http://bcn.iums.ac.ir/browse.php?a_code=A-10-4292-1&slc_lang=en&sid=1 Dina Gholipour dinagholipour@yahoo.com 13700319475328460047859 13700319475328460047859 No Student Research Committee, Zahedan University of Medical Sciences, Zahedan, Iran. Mansour Shahraki shahrakimansour@yahoo.com 13700319475328460047860 13700319475328460047860 No Department of Nutrition, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran. Mohsen Saravani moh.saravani@gmail.com 13700319475328460047861 13700319475328460047861 No Cellular and Molecular Research Center, Resistant Tuberculosis Institute, Zahedan University of Medical Sciences, Zahedan, Iran. Abolfazl Payandeh payandeh61@gmail.com 13700319475328460047862 13700319475328460047862 No Community Nursing Research Center, Zahedan University of Medical Sciences, Zahedan, Iran. Hadi Eslahi hadi_eslahi2015@yahoo.com 13700319475328460047863 13700319475328460047863 Yes Student Research Committee, Zahedan University of Medical Sciences, Zahedan, Iran.