The Effects of Allopurinol on Major Depressive Disorder

Abstract

Background and Aim: Major Depressive Disorder (MDD) is the most common mental health condition, with a severe decline in performance, disability, and a 15% risk of suicide. Allopurinol increases the level of tryptophan in the body by inhibiting xanthine oxidase, and by elevating the level of tryptophan, i.e., a precursor to serotonin. Accordingly, it can improve the symptoms of depression. This study aimed to investigate the impact of allopurinol on MDD. Methods & Materials: In this double-blind clinical trial, 70 patients with MDD, diagnosed based on the Diagnostic and Statistical Manual of Mental Disorders- Fourth Edition-Third Edition (DSM IV-TR) were randomly (paired & individual patient records) divided into two equal groups. Both research groups received 40 mg of citalopram daily for 6 weeks. In addition to citalopram, the intervention group received 300 mg allopurinol daily and the control group received a placebo. At the end of the third and sixth weeks, the examined patients were tested for Hamilton Depression Rating Scale (HDRS). Ethical Considerations: This study was approved by the Ethics Committee of the Arak University of Medical Sciences (Code: IR.ARAKMU.REC.1394.68). Also, it was approved by the Iranian Registry of Clinical Trials (Code: IRCT201508277373n6). Results: The Mean±SD HDRS’s score, after 3 weeks of treatment, in the control and allopurinol groups was measured as 28.42±3.1 and 23.02±3.4, respectively. After 6 weeks after treatment, the Mean±SD depression score in the control and allopurinol groups was equal to 23.28±4.1 and 20.4±1.2, in sequence. A significant difference was observed between the research groups; thus, the intervention group obtained a lower mean score in the HDRS than the controls. Conclusion: Allopurinol can improve the symptoms of depression and can also be used as an adjunct in the treatment of depression.