Association between impairment of lung function and risk of anxiety and depression in patients with chronic obstructive pulmonary disease—a systematic review

BACKGROUND: This systematic review aims to examine the association between impairment of lung function and risk of anxiety and depression, respectively, in patients with chronic obstructive pulmonary disease (COPD). METHODS: Literature search were performed 29/01-2024 using Embase and PubMed. Publications reporting association between forced expiratory volume in one second in percentage of expected value (FEV1(%)) and either anxiety or depression or both in patients with COPD were included. The studies were quality assessed using the Newcastle Ottawa Scale. The studies were analysed by assessing whether they showed significant results or not, and if they showed a negative or positive association between lung function and risk anxiety or depression and a pooled analysis was conducted. RESULTS: Thirty-seven studies were included in the review, 15 reported anxiety and 31 reported depression, with 9 reporting both outcomes. Most were observational studies. Study population sizes ranged from 40 to 2147 patients. Three studies found a significant negative association between anxiety and FEV1(%), while five studies found a positive non-significant association between anxiety and FEV1(%). Fifteen studies found a significant negative association between FEV1(%) and depression. Especially the studies with larger study population sizes showed significant results. The pooled analysis supported this, as the depression studies showed a significant association between depression and FEV1(%), while the anxiety studies showed part non-significant, part significant associations between anxiety and FEV1(%). CONCLUSION: This systematic review did not support an association between anxiety and impairment of pulmonary function as only 3/15 studies showed significant negative associations, and some studies showed positive associations. This review indicated an association between depression and impairment pulmonary function in patients with COPD, as most studies with a larger study population size showed a significant negative association. Sytematic review registration. PROSPERO 2024 CRD42024506065 Available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024506065.