{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,18]],"date-time":"2026-06-18T23:43:16Z","timestamp":1781826196627,"version":"3.54.5"},"reference-count":48,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2024,12,24]],"date-time":"2024-12-24T00:00:00Z","timestamp":1734998400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Medicina"],"abstract":"<jats:p>Background and Objectives: Oxidative stress has been identified as a key process involved in different diseases, particularly depression. Selenium (Se) protects against oxidative stress, one of the pathogenic mechanisms involved in affective disorders. Selenium is incorporated into antioxidant selenoproteins, such as selenoprotein P, which acts as the main selenium-transport protein in plasma and as an extracellular oxidant defense mechanism. This study aimed to determine whether lower selenium and selenoprotein P levels correlate with high levels of depression and anxiety symptoms. Materials and Methods: The research design was a quantitative cross-sectional study among employed fourth-year medical students at Riga Stradins University in Latvia. The respondents were selected using convenience samples. The symptoms of anxiety were assessed using the Generalized Anxiety Disorder-7 (GAD-7) scale, and the symptoms of depression were assessed using the Patient Health Questionnaire-9 (PHQ-9) scale. Results: A total of 32 respondents participated; 90.6% (n = 29) were female. A significant association was found between selenoprotein P and symptoms of depression (p = 0.006), as well as between selenoprotein P and symptoms of anxiety (p = 0.012). The median selenium level was not significantly lower (p = 0.214) in the study group compared to the control group. Conclusions: There is a statistically significant correlation between selenoprotein P and symptoms of depression and anxiety, and there is a tendency for students with symptoms of depression and anxiety to have lower selenium levels. However, alternative unrecognized oxidative stress mechanisms involved in the development of symptoms of depression and anxiety, involving selenium and selenoprotein P pathways, may exist. Consequently, further research assessing possible alternative pathways and the effect size is required.<\/jats:p>","DOI":"10.3390\/medicina61010003","type":"journal-article","created":{"date-parts":[[2024,12,24]],"date-time":"2024-12-24T09:00:57Z","timestamp":1735030857000},"page":"3","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["The Association of Plasma Selenium and Selenoprotein P Levels with Depression Severity and Anxiety Symptoms Among Medical Students in Latvia"],"prefix":"10.3390","volume":"61","author":[{"given":"Zanda","family":"Bir\u0123ele","sequence":"first","affiliation":[{"name":"Clinic of Psychosomatic medicine and Psychotherapy, Riga Stradi\u0146\u0161 University, LV-1046 Riga, Latvia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paula Marija","family":"Vimba","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, Riga Stradi\u0146\u0161 University, LV-1007 Riga, Latvia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-6617-0245","authenticated-orcid":false,"given":"Anastasija","family":"\u0160ev\u010denko","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, Riga Stradi\u0146\u0161 University, LV-1007 Riga, Latvia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3726-8724","authenticated-orcid":false,"given":"Andrejs","family":"\u0160\u0137esters","sequence":"additional","affiliation":[{"name":"Institute of Occupational Safety and Environmental Health, Riga Stradi\u0146\u0161 University, LV-1067 Riga, Latvia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gunta","family":"Anc\u0101ne","sequence":"additional","affiliation":[{"name":"Department of Psychosomatic Medicine and Psychotherapy, Riga Stradi\u0146\u0161 University, LV-1046 Riga, Latvia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1478-3363","authenticated-orcid":false,"given":"Laura","family":"Valaine","sequence":"additional","affiliation":[{"name":"Department of Psychosomatic Medicine and Psychotherapy, Riga Stradi\u0146\u0161 University, LV-1046 Riga, Latvia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,12,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Kupcova, I., Danisovic, L., Klein, M., and Harsanyi, S. (2023). Effects of the COVID-19 pandemic on mental health, anxiety, and depression. BMC Psychol., 11.","DOI":"10.1186\/s40359-023-01130-5"},{"key":"ref_2","unstructured":"COVID-19 Mental Disorders Collaborators (2021). Global prevalence and burden of depressive and anxiety disorders in 204 countries and territories in 2020 due to the COVID-19 pandemic. Lancet, 398, 1700\u20131712."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Correia, A.S., Cardoso, A., and Vale, N. (2023). Oxidative Stress in Depression: The Link with the Stress Response, Neuroinflammation, Serotonin, Neurogenesis and Synaptic Plasticity. Antioxidants, 12.","DOI":"10.3390\/antiox12020470"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"737","DOI":"10.1080\/10715762.2018.1475733","article-title":"The role of oxidative stress in anxiety disorder: Cause or consequence?","volume":"52","author":"Fedoce","year":"2018","journal-title":"Free Radic. Res."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"63","DOI":"10.4161\/oxim.2.2.7944","article-title":"Oxidative stress and anxiety: Relationship and cellular pathways","volume":"2","author":"Bouayed","year":"2009","journal-title":"Oxidative Med. Cell. Longev."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"100263","DOI":"10.1016\/j.phanu.2021.100263","article-title":"Selenium supplementation and oxidative stress: A review","volume":"17","author":"Zakeri","year":"2021","journal-title":"PharmaNutrition"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"152","DOI":"10.1016\/j.abb.2013.02.021","article-title":"Selenium homeostasis and antioxidant selenoproteins in brain: Implications for disorders in the central nervous system","volume":"536","author":"Steinbrenner","year":"2013","journal-title":"Arch. Biochem. Biophys."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"608","DOI":"10.3390\/futurepharmacol2040037","article-title":"Selenium and Its Compounds in the Treatment of Anxiety and Related Disorders: A Scoping Review of Translational and Clinical Research","volume":"2","author":"Rajkumar","year":"2022","journal-title":"Futur. Pharmacol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1558","DOI":"10.1016\/S1734-1140(13)71517-2","article-title":"Oxidative stress markers in affective disorders","volume":"65","author":"Siwek","year":"2013","journal-title":"Pharmacol. Rep."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"451","DOI":"10.1007\/s42000-019-00143-3","article-title":"Effect of selenium supplementation on antioxidant markers: A systematic review and meta-analysis of randomized controlled trials","volume":"18","author":"Hasani","year":"2019","journal-title":"Hormones"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Wang, J., Um, P., Dickerman, B.A., and Liu, J. (2018). Zinc, Magnesium, Selenium and Depression: A Review of the Evidence, Potential Mechanisms and Implications. Nutrients, 10.","DOI":"10.3390\/nu10050584"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Sajjadi, S.S., Foshati, S., Haddadian-Khouzani, S., and Rouhani, M.H. (2022). The role of selenium in depression: A systematic review and meta-analysis of human observational and interventional studies. Sci. Rep., 12.","DOI":"10.1038\/s41598-022-05078-1"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1016\/j.freeradbiomed.2018.02.030","article-title":"Selenium, selenoprotein P, and Alzheimer's disease: Is there a link?","volume":"127","author":"Solovyev","year":"2018","journal-title":"Free. Radic. Biol. Med."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1441","DOI":"10.1016\/j.bbagen.2009.03.026","article-title":"Selenoprotein P-expression, functions, and roles in mammals","volume":"1790","author":"Burk","year":"2009","journal-title":"Biochim. Biophys. Acta"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"186","DOI":"10.1016\/j.psychres.2017.05.027","article-title":"Prevalence of psychological stress, depression and anxiety among medical students in Egypt","volume":"255","author":"Fawzy","year":"2017","journal-title":"Psychiatry Res."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"391","DOI":"10.1016\/j.jpsychires.2012.11.015","article-title":"A systematic review of studies of depression prevalence in university students","volume":"47","author":"Ibrahim","year":"2013","journal-title":"J. Psychiatr. Res."},{"key":"ref_17","first-page":"122","article-title":"Depression, anxiety and their associated factors among medical students","volume":"20","author":"Alvi","year":"2010","journal-title":"J. Coll. Physicians Surg. Pak."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"233","DOI":"10.1590\/1516-4446-2013-1183","article-title":"First- and last-year medical students: Is there a difference in the prevalence and intensity of anxiety and depressive symptoms?","volume":"36","author":"Bassols","year":"2014","journal-title":"Rev. Bras. Psiquiatr."},{"key":"ref_19","first-page":"699","article-title":"Anxiety and depression among medical students: A cross-sectional study","volume":"60","author":"Jadoon","year":"2010","journal-title":"J. Pak. Med. Assoc."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"456","DOI":"10.1111\/medu.12962","article-title":"Prevalence of depression amongst medical students: A meta-analysis","volume":"50","author":"Puthran","year":"2016","journal-title":"Med. Educ."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"963","DOI":"10.1111\/medu.12512","article-title":"Medical student depression, anxiety and distress outside North America: A systematic review","volume":"48","author":"Hope","year":"2014","journal-title":"Med. Educ."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"e1","DOI":"10.1016\/j.jcrc.2009.06.003","article-title":"Cognitive emotions: Depression and anxiety in medical students and staff","volume":"24","author":"Ahmed","year":"2009","journal-title":"J. Crit. Care"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1181","DOI":"10.1001\/jama.2010.1300","article-title":"Depression, stigma, and suicidal ideation in medical students","volume":"304","author":"Schwenk","year":"2010","journal-title":"JAMA"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"594","DOI":"10.1111\/j.1365-2929.2005.02176.x","article-title":"Stress and depression among medical students: A cross-sectional study","volume":"39","author":"Dahlin","year":"2005","journal-title":"Med. Educ."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"435","DOI":"10.1111\/j.1440-1819.2010.02109.x","article-title":"Anxiety, neuroticism and oxidative stress","volume":"64","author":"Matsushita","year":"2010","journal-title":"Psychiatry Clin. Neurosci."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1080\/08964280309596057","article-title":"Changes in clinically relevant metabolites with psychological stress parameters","volume":"29","author":"Hapuarachchi","year":"2003","journal-title":"Behav. Med."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"112","DOI":"10.1080\/08039488.2017.1397191","article-title":"Adaptation and validation of the Patient Health Questionnaire-9 to evaluate major depression in a primary care sample in Latvia","volume":"72","author":"Vrublevska","year":"2018","journal-title":"Nord. J. Psychiatry"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"606","DOI":"10.1046\/j.1525-1497.2001.016009606.x","article-title":"The PHQ-9: Validity of a brief depression severity measure","volume":"16","author":"Kroenke","year":"2001","journal-title":"J. Gen. Intern. Med."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1092","DOI":"10.1001\/archinte.166.10.1092","article-title":"A brief measure for assessing generalized anxiety disorder: The GAD-7","volume":"166","author":"Spitzer","year":"2006","journal-title":"Arch. Intern. Med."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"184","DOI":"10.1136\/ebm.11.6.184","article-title":"The GAD-7 scale was accurate for diagnosing generalised anxiety disorder","volume":"11","author":"Swinson","year":"2006","journal-title":"Evid. Based Med."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Vrublevska, J., Renemane, L., Kivite-Urtane, A., and Rancans, E. (2022). Validation of the generalized anxiety disorder scales (GAD-7 and GAD-2) in primary care settings in Latvia. Front. Psychiatry, 13.","DOI":"10.3389\/fpsyt.2022.972628"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"127","DOI":"10.4103\/0972-6748.151684","article-title":"Oxidative stress and psychological functioning among medical students","volume":"23","author":"Srivastava","year":"2014","journal-title":"Ind. Psychiatry J."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"183","DOI":"10.1080\/10253890400012685","article-title":"Oxidative stress in university students during examinations","volume":"7","year":"2004","journal-title":"Stress"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1016\/S0003-2670(00)85199-5","article-title":"A micromethod for the determination of selenium in tissues and biological fluids by single-test-tube fluorimetry","volume":"165","author":"Alfthan","year":"1984","journal-title":"Anal. Chim. Acta"},{"key":"ref_35","unstructured":"(2024, August 19). Human Selenoprotein P(SEPP1) ELISA Kit. Available online: https:\/\/www.cusabio.com\/ELISA-Kit\/Human-Selenoprotein-PSEPP1-ELISA-kit-102874.html."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"671377","DOI":"10.3389\/fnut.2021.671377","article-title":"Association of Selenium Intake and Development of Depression in Brazilian Farmers","volume":"8","author":"Petarli","year":"2021","journal-title":"Front Nutr."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"e121","DOI":"10.1016\/j.pedn.2021.09.026","article-title":"Lower serum selenium concentration associated with anxiety in children","volume":"63","author":"Portnoy","year":"2022","journal-title":"J. Pediatr. Nurs."},{"key":"ref_38","first-page":"232","article-title":"The Relationship of Dietary Intake of Zinc, Selenium, and Magnesium and Anthropometric Profiles with Depression in Female Medical Students at Zahedan University of Medical Sciences","volume":"6","author":"Shokati","year":"2021","journal-title":"J. Nutr. Food Secur."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"59","DOI":"10.3945\/jn.114.198010","article-title":"Optimal serum selenium concentrations are associated with lower depressive symptoms and negative mood among young adults","volume":"145","author":"Conner","year":"2015","journal-title":"J. Nutr."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"102","DOI":"10.1007\/s12199-007-0019-4","article-title":"Selenium: Its role as antioxidant in human health","volume":"13","author":"Tinggi","year":"2008","journal-title":"Environ. Health Prev. Med."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Dogaru, C.B., Muscurel, C., Du\u021b\u0103, C., and Stoian, I. (2023). \u201cAlphabet\u201d Selenoproteins: Their Characteristics and Physiological Roles. Int. J. Mol. Sci., 24.","DOI":"10.3390\/ijms242115992"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"307","DOI":"10.1152\/physiol.00021.2006","article-title":"Selenoproteins and their impact on human health through diverse physiological pathways","volume":"21","author":"Moghadaszadeh","year":"2006","journal-title":"Physiology"},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Saito, Y. (2021). Selenium Transport Mechanism via Selenoprotein P-Its Physiological Role and Related Diseases. Front. Nutr., 8.","DOI":"10.3389\/fnut.2021.685517"},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Amirkhizi, F., Khalese-Ranjbar, B., Mansouri, E., Hamedi-Shahraki, S., and Asghari, S. (2023). Correlations of selenium and selenoprotein P with asymmetric dimethylarginine and lipid profile in patients with polycystic ovary syndrome. J. Trace Elements Med. Biol., 75.","DOI":"10.1016\/j.jtemb.2022.127101"},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Barchielli, G., Capperucci, A., and Tanini, D. (2022). The Role of Selenium in Pathologies: An Updated Review. Antioxidants, 11.","DOI":"10.3390\/antiox11020251"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"e39115","DOI":"10.1097\/MD.0000000000039115","article-title":"Comparison of depression and anxiety in first- versus non-first generation Saudi medical students: A cross-sectional study","volume":"103","author":"Almadani","year":"2024","journal-title":"Medicine"},{"key":"ref_47","first-page":"e-195874","article-title":"Anxiety and depression in medical students: A cross-sectional study","volume":"101","author":"Nunes","year":"2022","journal-title":"Rev. Med."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"31","DOI":"10.4103\/cmi.cmi_81_22","article-title":"Anxiety, Depression and Stress Among Female Medical Students During the Second Wave of the COVID-19 Pandemic and their Association with Family Functioning, Coping and Personality","volume":"21","author":"Mallaram","year":"2023","journal-title":"Curr. Med Issues"}],"container-title":["Medicina"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1648-9144\/61\/1\/3\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T16:59:09Z","timestamp":1760115549000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1648-9144\/61\/1\/3"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,12,24]]},"references-count":48,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2025,1]]}},"alternative-id":["medicina61010003"],"URL":"https:\/\/doi.org\/10.3390\/medicina61010003","relation":{},"ISSN":["1648-9144"],"issn-type":[{"value":"1648-9144","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,12,24]]}}}