Background: exacerbations are common in chronic obstructive pulmonary disease (COPD) and contribute significantly to COPD morbidity and mortality. COPD is also associated with high levels of psychological distress, which has been shown to be associated with higher exacerbation rates. However, the existing literature on the association between psychological distress and exacerbation risk remains largely misunderstood.
Objectives: to critically review the current literature on the association between psychological distress (defined as anxiety and depressive symptoms or anxiety and depressive disorders) and COPD exacerbations in COPD patients, to highlight the limitations of the existing literature, and to provide recommendations for future research.
Methods: a critical review of English-language peer-reviewed longitudinal and retrospective studies was conducted. The Ovid portal to Medline, EMBASE, and PsycINFO databases were accessed.
Results: some acceptable evidence suggested that psychological distress confers greater risk for exacerbations, more specifically symptom-based exacerbations or those treated in the patient's own environment. However, most studies showed an absence of a positive association, especially with exacerbations leading to hospitalization.
Conclusions: methodological weaknesses and the use of a wide range of psychological tools mean that there is an inconsistent association between psychological distress and exacerbations in the current literature. However, psychological distress may confer greater risk for symptom-based rather than event-based defined exacerbations. Further studies are needed to more comprehensively assess the question, particularly in light of the high levels of both anxiety and depression in COPD patients.