Self-report questionnaires
Depression, breathlessness, Anxiety, Fatigue
All questionnaires (List of measures included within each of the three models (indicated by ‘X’)Drug ID labels corresponded to whether the participant received D-cycloserine or placebo.BCS, breathlessness catastrophising scale; BMI, body mass index; BORG, rating of perceived exertion; CES-D, Centre for Epidemiologic Studies Depression Scale; D12, Dyspnoea-12; FEV1, forced expiratory volume; FSS, Fatigue Severity Scale; FVC, forced vital capacity; HR, heart rate; MRC, Medical Research Council; MSWT, Modified Shuttle Walk Test; SGRQ, St George’s Respiratory Questionnaire; SPO2, oxygen saturation; TRAIT, Trait Anxiety Inventory.