Nana Brochmann,1 Esben Meulengracht Flachs,2 Anne Illemann Christensen,3 Marie Bak,1 Christen Lykkegaard Andersen,1 Knud Juel,3 Hans Carl Hasselbalch,1 Ann-Dorthe Zwisler,4 Nina Rottmann4–6 1Department of Hematology, Zealand University Hospital, University of Copenhagen, Roskilde, Denmark; 2Department of Occupational and Environmental Medicine, Bispebjerg University Hospital, Copenhagen, Denmark; 3National Institute of Public Health, University of Southern Denmark, Copenhagen, Denmark; 4Danish Knowledge Centre for Rehabilitation and Palliative Care, Odense University Hospital, University of Southern Denmark, Nyborg, Denmark; 5Department of Psychology, University of Southern Denmark, Odense, Denmark; 6Research Unit of General Practice, Department of Public Health, University of Southern Denmark, Odense, Denmark Objective: We sought to determine the prevalence and severity of anxiety and depression among patients with Philadelphia-negative myeloproliferative neoplasms (MPNs) and respective associations of anxiety and depression with demographic and lifestyle factors, comorbidity burden, duration of MPN disease, financial difficulties, and health-related quality of life (QoL). Methods: This study used data from a nationwide, population-based, cross-sectional survey of health-related QoL in MPN patients in Denmark called the MPNhealthSurvey. Individuals with a diagnosis of MPN in the National Patient Register were invited. The Hospital Anxiety and Depression Scale was used to assess the prevalence and severity of anxiety and depression. The associations of anxiety and depression with age, sex, education, body mass index (BMI), smoking, alcohol intake, physical activity, comorbidity burden, duration of MPN disease, financial difficulties, symptom burden, sexual problems, fatigue, functioning, and global health/QoL were examined. Results: In total, 2,029 patients completed the Hospital Anxiety and Depression Scale. The prevalence of anxiety, depression, and both was 21%, 12%, and 8%, respectively. Many participants who reported anxiety or depression exhibited mild symptoms. Middle-aged and elderly participants had lower odds of experiencing anxiety and depression when compared to younger participants, and females had higher odds of anxiety compared to males. Participants with higher education had lower odds of anxiety compared to those with lower education. Current smokers and ex-smokers had higher odds of anxiety and depression compared to those who had never smoked, and sedentary participants and participants with a lower level of physical activity had higher odds of anxiety and depression compared to participants who performed hard training several times a week. Higher comorbidity burden increased the odds of depression, and greater financial difficulties increased the odds of anxiety and depression. Higher total symptom burden and fatigue burden and higher level of sexual problems increased the odds of anxiety and depression. Finally, lower functional level and global health/quality of life increased the odds of anxiety and depression. BMI, alcohol intake, comorbidity burden, and duration of disease were not substantially associated with anxiety, whereas sex, educational level, and duration of MPN disease were not substantially associated with depression. Conclusion: There may be an unmet need in handling psychological distress in MPN patients. Future research might explore the utility of screening for psychological distress and the effectiveness of lifestyle interventions, rehabilitation, and MPN-symptom reduction in preventing and treating psychological distress. Keywords: myeloproliferative neoplasm, anxiety, depression, health-related quality of life, patient-reported outcomes