{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,12]],"date-time":"2026-03-12T19:17:10Z","timestamp":1773343030224,"version":"3.50.1"},"reference-count":48,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2026,3,12]],"date-time":"2026-03-12T00:00:00Z","timestamp":1773273600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background\/Objectives: University students are particularly vulnerable to psychological distress and sleep disturbances, which may impair academic performance and overall well-being. Lifestyle changes, increased academic demands, and the COVID-19 pandemic may have further exacerbated these problems. This study aimed to assess the prevalence of insomnia and anxiety among students at the University of Rijeka and to examine their associations with COVID-19 infection, vaccination status, lifestyle habits, and sociodemographic characteristics. Methods: A cross-sectional online survey was conducted between October 2024 and April 2025 among 594 students from 14 faculties of the University of Rijeka. Data were collected using a self-administered questionnaire including sociodemographic variables, the Insomnia Severity Index (ISI), the Generalized Anxiety Disorder-7 (GAD-7), lifestyle behaviors, and COVID-19-related factors. Statistical significance was set at p &lt; 0.05. Results: Insomnia was reported by 50.7% of students (36.9% mild, 12.1% moderate, 1.7% severe), while 49.6% reported elevated anxiety levels. Female sex, smoking, low physical activity, poor subjective sleep quality, and frequent nighttime awakenings were significantly associated with higher ISI and GAD-7 scores (all p &lt; 0.05). COVID-19 infection and vaccination status showed weaker associations with insomnia compared to psychosocial and lifestyle factors. Students living in shared rental accommodation reported higher insomnia severity. In multivariable regression analysis, anxiety severity, sleep fragmentation (frequent nocturnal awakenings), and poor perceived sleep quality emerged as the strongest independent predictors of insomnia severity. Conclusions: Insomnia and anxiety are highly prevalent among University of Rijeka students and are primarily associated with psychosocial and lifestyle factors rather than COVID-19-related variables. University-based interventions focusing on stress reduction, sleep hygiene, and early mental health support are warranted, particularly for high-risk groups.<\/jats:p>","DOI":"10.3390\/jcm15062157","type":"journal-article","created":{"date-parts":[[2026,3,12]],"date-time":"2026-03-12T09:23:03Z","timestamp":1773307383000},"page":"2157","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["The Prevalence of Sleep Disturbances and Anxiety Among Croatian University Students: Possible Association with Lifestyle Factors and COVID-19"],"prefix":"10.3390","volume":"15","author":[{"given":"Tina","family":"Zavidi\u0107","sequence":"first","affiliation":[{"name":"Department of Family Medicine, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ema","family":"Dejhalla","sequence":"additional","affiliation":[{"name":"Medical Centre for Occupational Health Rijeka, Family Medicine Office, 51000 Rijeka, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ana","family":"Lesac Brizi\u0107","sequence":"additional","affiliation":[{"name":"Department of Family Medicine, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tatjana","family":"\u010culina","sequence":"additional","affiliation":[{"name":"Department of Family Medicine, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Branislava","family":"Popovi\u0107","sequence":"additional","affiliation":[{"name":"Department of Family Medicine, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"469","DOI":"10.1037\/0003-066X.55.5.469","article-title":"Emerging adulthood: A theory of development from the late teens through the twenties","volume":"55","author":"Arnett","year":"2000","journal-title":"Am. Psychol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"90","DOI":"10.1016\/j.jad.2014.10.054","article-title":"The prevalence and correlates of depression, anxiety, and stress in a sample of college students","volume":"173","author":"Beiter","year":"2015","journal-title":"J. Affect. Disord."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"73","DOI":"10.2147\/NSS.S62907","article-title":"Causes and consequences of sleepiness among college students","volume":"6","author":"Hershner","year":"2014","journal-title":"Nat. Sci. Sleep"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1016\/j.jadohealth.2009.06.016","article-title":"Sleep patterns and predictors of disturbed sleep in a large population of college students","volume":"46","author":"Lund","year":"2010","journal-title":"J. Adolesc. Health"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2955","DOI":"10.1017\/S0033291716001665","article-title":"Mental disorders among college students in the WHO World Mental Health Surveys","volume":"46","author":"Auerbach","year":"2016","journal-title":"Psychol. Med."},{"key":"ref_6","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_7","doi-asserted-by":"crossref","first-page":"122","DOI":"10.1016\/j.jpsychires.2018.01.009","article-title":"Sleep problems and suicidal behaviors in college students","volume":"99","author":"Becker","year":"2018","journal-title":"J. Psychiatr. Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1059","DOI":"10.5665\/sleep.2810","article-title":"A Systematic Review Assessing Bidirectionality between Sleep Disturbances, Anxiety, and Depression","volume":"36","author":"Alvaro","year":"2013","journal-title":"Sleep"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1016\/j.jad.2011.01.011","article-title":"Insomnia as a predictor of depression: A meta-analytic evaluation of longitudinal epidemiological studies","volume":"135","author":"Baglioni","year":"2011","journal-title":"J. Affect. Disord."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"339","DOI":"10.1016\/j.beth.2012.12.001","article-title":"Epidemiology of insomnia in college students: Relationship with mental health, quality of life, and substance use difficulties","volume":"44","author":"Taylor","year":"2013","journal-title":"Behav. Ther."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"168","DOI":"10.1111\/j.1749-6632.2009.04416.x","article-title":"The role of sleep in cognition and emotion","volume":"1156","author":"Walker","year":"2009","journal-title":"Ann. N. Y. Acad. Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"105","DOI":"10.1016\/B978-0-444-53702-7.00007-5","article-title":"Effects of sleep deprivation on cognition","volume":"185","author":"Killgore","year":"2010","journal-title":"Prog. Brain Res."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1025","DOI":"10.1016\/j.adolescence.2013.08.007","article-title":"The impact of sleep on adolescent depressed mood, alertness and academic performance","volume":"36","author":"Short","year":"2013","journal-title":"J. Adolesc."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1007\/s10802-005-1824-0","article-title":"Prospective longitudinal associations between persistent sleep problems in childhood and anxiety and depression disorders in adulthood","volume":"33","author":"Gregory","year":"2005","journal-title":"J. Abnorm. Child Psychol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"e13052","DOI":"10.1111\/jsr.13052","article-title":"Dealing with sleep problems during home confinement due to the COVID-19 outbreak: Practical recommendations from a task force of the European CBT-I Academy","volume":"29","author":"Altena","year":"2020","journal-title":"J. Sleep Res."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"370","DOI":"10.4103\/psychiatry.IndianJPsychiatry_523_20","article-title":"Changes in sleep pattern and sleep quality during COVID-19 lockdown","volume":"62","author":"Gupta","year":"2020","journal-title":"Indian J. Psychiatry"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"299","DOI":"10.5664\/jcsm.8930","article-title":"Sleep problems during the COVID-19 pandemic by population: A systematic review and meta-analysis","volume":"17","author":"Jahrami","year":"2021","journal-title":"J. Clin. Sleep Med."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"416","DOI":"10.1016\/S2215-0366(21)00084-5","article-title":"6-month neurological and psychiatric outcomes in 236\u2009379 survivors of COVID-19: A retrospective cohort study using electronic health records","volume":"8","author":"Taquet","year":"2021","journal-title":"Lancet Psychiatry"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Elboraay, T., Ebada, M.A., Elsayed, M., Aboeldahab, H.A., Salamah, H.M., Rageh, O., Elmallahy, M., AboElfarh, H.E., Mansour, L.S., and Nabil, Y. (2025). Long-term neurological and cognitive impact of COVID-19: A systematic review and meta-analysis in over 4 million patients. BMC Neurol., 25.","DOI":"10.1186\/s12883-025-04174-9"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"04282","DOI":"10.7189\/jogh.15.04282","article-title":"Prevalence and duration of common symptoms in people with long COVID: A systematic review and meta-analysis","volume":"15","author":"Luo","year":"2025","journal-title":"J. Glob. Health"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"100980","DOI":"10.1016\/j.bbih.2025.100980","article-title":"Subjective cognitive, psychiatric, and fatigue symptoms two years after COVID-19: A prospective longitudinal cohort study","volume":"45","author":"Ollila","year":"2025","journal-title":"Brain Behav. Immun.\u2014Health"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1758","DOI":"10.1038\/s41598-024-52005-7","article-title":"Microstructural brain abnormalities, fatigue, and cognitive dysfunction after mild COVID-19","volume":"14","author":"Bechelli","year":"2024","journal-title":"Sci. Rep."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1007\/s00424-011-1044-0","article-title":"Sleep and immune function","volume":"463","author":"Besedovsky","year":"2012","journal-title":"Pfl\u00fcgers Arch.\u2014Eur. J. Physiol."},{"key":"ref_24","first-page":"1063","article-title":"Sleep and antibody response to hepatitis B vaccination","volume":"35","author":"Prather","year":"2012","journal-title":"Sleep"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1471","DOI":"10.1001\/jama.288.12.1471-a","article-title":"Effect of sleep deprivation on response to immunization","volume":"288","author":"Spiegel","year":"2002","journal-title":"JAMA"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Benedict, C., Brytting, M., Markstr\u00f6m, A., Broman, J.E., and Schi\u00f6th, H.B. (2012). Acute sleep deprivation has no lasting effects on the human antibody titer response following a novel influenza A H1N1 virus vaccination. BMC Immunol., 13.","DOI":"10.1186\/1471-2172-13-1"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1080\/07448481.2023.2185451","article-title":"Sleep difficulties and psychological distress among college students during a COVID-19 campus red alert","volume":"73","author":"Samuolis","year":"2025","journal-title":"J. Am. Coll. Health"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1323","DOI":"10.1080\/07448481.2021.1928143","article-title":"Stress, anxiety, and sleep among college and university students during the COVID-19 pandemic","volume":"71","author":"Ulrich","year":"2023","journal-title":"J. Am. Coll. Health"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Alyoubi, A., Halstead, E.J., Zambelli, Z., and Dimitriou, D. (2021). The Impact of the COVID-19 Pandemic on Students\u2019 Mental Health and Sleep in Saudi Arabia. Int. J. Environ. Res. Public Health, 18.","DOI":"10.3390\/ijerph18179344"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"113863","DOI":"10.1016\/j.psychres.2021.113863","article-title":"The prevalence of depressive symptoms, anxiety symptoms and sleep disturbance in higher education students during the COVID-19 pandemic: A systematic review and meta-analysis","volume":"301","author":"Deng","year":"2021","journal-title":"Psychiatry Res."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1002\/smi.3171","article-title":"Impact of COVID-19 pandemic on sleep of undergraduate students: A systematic literature review","volume":"39","author":"Valenzuela","year":"2023","journal-title":"Stress Health"},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Silva, G., Estima, F., Silva, A.C., Mota, J., Martins, C., and Aires, L. (2025). Mental Health in Young Adult University Students During COVID-19 Lockdown: Associations with Physical Activity, Sedentary Behaviors and Sleep Quality. Int. J. Environ. Res. Public Health, 22.","DOI":"10.3390\/ijerph22020241"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"297","DOI":"10.1016\/S1389-9457(00)00065-4","article-title":"Validation of the Insomnia Severity Index as an outcome measure for insomnia research","volume":"2","author":"Bastien","year":"2001","journal-title":"Sleep Med."},{"key":"ref_34","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_35","doi-asserted-by":"crossref","unstructured":"Ahmed, I., Hazell, C.M., Edwards, B., Glazebrook, C., and Davies, E.B. (2023). A systematic review and meta-analysis of studies exploring prevalence of non-specific anxiety in undergraduate university students. BMC Psychiatry, 23.","DOI":"10.1186\/s12888-023-04645-8"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Zhu, Y., Liang, W.M., Jiang, K., Truskauskait\u0117, I., Gri\u0161kova-Bulanova, I., Bai, Z., and Ruk\u0161\u0117nas, O. (2025). Mental well-being of college students: Focus on sex differences and psychophysiological indices. BMC Public Health, 25.","DOI":"10.1186\/s12889-025-24231-9"},{"key":"ref_37","first-page":"e128","article-title":"Exploring sleep patterns in 3475 college students: A comparative study of geographical location, gender, and age","volume":"18","author":"Romdhani","year":"2024","journal-title":"Sleep Sci."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"e70110","DOI":"10.1111\/jsr.70110","article-title":"Insomnia disorder: Gender issues over the lifespan","volume":"34","author":"Baldi","year":"2025","journal-title":"J. Sleep Res."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"3241","DOI":"10.2147\/NDT.S187419","article-title":"The association between depression, anxiety and substance use among Canadian post-secondary students","volume":"14","author":"Esmaeelzadeh","year":"2018","journal-title":"Neuropsychiatr. Dis. Treat."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"D\u0105browska-Galas, M., Ptaszkowski, K., and D\u0105browska, J. (2021). Physical activity level, insomnia and related impact in medical students in Poland. Int. J. Environ. Res. Public Health, 18.","DOI":"10.3390\/ijerph18063081"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"zsab187","DOI":"10.1093\/sleep\/zsab187","article-title":"Daily-level effects of alcohol, marijuana, and simultaneous use on young adults\u2019 perceived sleep health","volume":"44","author":"Graupensperger","year":"2021","journal-title":"Sleep"},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Liu, M., Liu, H., Qin, Z., Tao, Y., Ye, W., and Liu, R. (2024). Effects of physical activity on depression, anxiety, and stress in college students: The chain-based mediating role of psychological resilience and coping styles. Front. Psychol., 15.","DOI":"10.3389\/fpsyg.2024.1396795"},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Peng, J., Liu, M., Wang, Z., Xiang, L., and Liu, Y. (2025). Anxiety and sleep hygiene among college students: A moderated mediating model. BMC Public Health, 25.","DOI":"10.1186\/s12889-025-24441-1"},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Huang, Y., Yang, L., Liu, Y., and Zhang, S. (2024). Effects of perceived stress on college students\u2019 sleep quality: A moderated chain mediation model. BMC Psychol., 12.","DOI":"10.1186\/s40359-024-01976-3"},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Hu, B., Wu, Q., Wang, Y., Zhou, H., and Yin, D. (2024). Factors associated with sleep disorders among university students in Jiangsu Province: A cross-sectional study. Front. Psychiatry, 15.","DOI":"10.3389\/fpsyt.2024.1288498"},{"key":"ref_46","first-page":"e61334","article-title":"The prevalence and predictors of sleep disorders and their impact on academic performance among Saudi university students: A cross-sectional study","volume":"16","author":"Alomri","year":"2024","journal-title":"Cureus"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"1530","DOI":"10.1378\/chest.116.6.1530","article-title":"Prevalence of snoring and sleep-disordered breathing in a student population","volume":"116","author":"Hui","year":"1999","journal-title":"Chest"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"2410","DOI":"10.1007\/s44411-025-00252-z","article-title":"Sex-Specific Interrelationships of Sleeping and Nutritional Habits with Somatic Health Indicators in Young Adults","volume":"126","author":"Sulis","year":"2025","journal-title":"Bratisl. Med. J."}],"container-title":["Journal of Clinical Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0383\/15\/6\/2157\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,12]],"date-time":"2026-03-12T10:14:31Z","timestamp":1773310471000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0383\/15\/6\/2157"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,12]]},"references-count":48,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2026,3]]}},"alternative-id":["jcm15062157"],"URL":"https:\/\/doi.org\/10.3390\/jcm15062157","relation":{},"ISSN":["2077-0383"],"issn-type":[{"value":"2077-0383","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3,12]]}}}