Associations Between Anxiety, Depression, and Disease Activity in Newly Diagnosed Patients with Inflammatory Bowel Disease: A Prospective Cohort Study

Background/Objectives: Psychological distress, including symptoms of anxiety and depression, is common among individuals with inflammatory bowel disease (IBD) and may adversely affect well-being and disease management. However, routine assessment of mental health is not consistently integrated into clinical care. This study assessed the prevalence of anxiety and depression among patients newly diagnosed with IBD at diagnosis and after three months of treatment and explored associations between psychological symptoms, disease activity, and clinical characteristics. Methods: This prospective cohort study included 304 adults newly diagnosed with IBD and treated at Stavanger University Hospital between 2012 and 2019. Symptoms of anxiety and depression were assessed using the Hospital Anxiety and Depression Scale at baseline and after three months. Disease activity was evaluated using the Harvey–Bradshaw Index and Partial Mayo Score. Clinical variables included C-reactive protein, faecal calprotectin, folate, cobalamin, and body mass index. Multivariable regression analyses were conducted to identify factors associated with psychological symptoms. Results: The prevalence of anxiety decreased from 29.8% at diagnosis to 21.6% after three months, while the prevalence of combined anxiety and depression declined from 22.2% to 16.3%. The prevalence of depression alone remained stable over time. Higher disease activity, particularly as measured by the Harvey–Bradshaw Index, showed the strongest association with anxiety and depressive symptoms. However, after adjustment for potential confounders, no significant improvement in psychological symptoms was observed, suggesting that the association between time and HADS scores may be explained by changes in one or more measured covariates. Conclusions: Psychological symptoms remained common during the first months following an IBD diagnosis and were closely associated with disease activity. Medical treatment alone was insufficient to achieve meaningful improvements in mental health outcomes. These findings highlight the importance of systematic psychological assessment, early identification of emotional distress, and integrated multidisciplinary care, including nursing-led screening and supportive interventions, for individuals newly diagnosed with IBD.