Risk of depression in patients with chronic obstructive pulmonary disease and its determinants.

BACKGROUND: Although it has been repeatedly suggested that chronic obstructive pulmonary disease (COPD) is associated with depression, no conclusion has so far been reached. A study was undertaken to investigate whether depression occurs more often in patients with COPD than in controls. The demographic and clinical variables associated with depression were also determined. METHODS: Patients with a registered diagnosis of obstructive airway disease in general practice, aged > or=40 years, forced expiratory volume in 1 second (FEV(1)) <80% predicted, FEV(1) reversibility