<qa>  What is the purpose of this double blind randomized controlled trial?Objectives of this double blind randomized controlled trial are to study the effect of oral administration of morphine SR on health-related quality of life, respiratory adverse effects, and functional capacity; to explore whether description and severity of breathlessness are related with a clinically relevant response to morphine and to analyse the cost-effectiveness of morphine SR. The study population will consist of 124 clinically stable outpatients with COPD and severe dyspnea despite optimal pharmacological and non-pharmacological treatment. 