Anxiety and depression symptoms in relation to lung function and Chronic Obstructive Pulmonary Disease (COPD) in 9000 adults - The HUNT 2 (1995-97) population study

Background: Anxiety and depression symptoms are highly prevalent in people with Chronic Obstructive Pulmonary Disease (COPD). However, there are few large studies of the general population that have investigated the association of anxiety and depression with lung function. Purpose: To investigate the relationship between anxiety and depression symptoms and lung function in a large adult population sample. Materials and methods: In this cross-sectional study we included 8,981 men and women from the Nord-Trøndelags Health Study, HUNT2 (1995-97), Norway. Symptoms of anxiety and depression were self-reported using the Hospital Anxiety and Depression Scale (HADS). Lung function was defined by spirometric values and categorized by GOLD – classification. Results: Participants with moderate and severe COPD had significant higher crude odds ratio for pure depression and mixed symptoms, yet this was mainly explained by differences in age and gender between the groups. In gender-stratified analysis women had increased odds for symptoms of depression and mixed symptoms due to exacerbated lung function. In contrast, men with severe COPD reported higher rates of symptoms of pure anxiety. However, statistical evidence was borderline in the fully adjusted models. Conclusion: Results from this study indicate a high prevalence of mental distress in severe COPD. Gender specific relations between symptoms of anxiety and depression and lung function was found; worsened lung function was associated with pure depression and mixed symptoms in women, while severe COPD was associated with pure anxiety in men. .These patterns might have clinical relevance and should be further investigated