Correlation of depression and cognitive function in patients with chronic obstructive pulmonary disease

Based upon the measure of depression as defined by Hamilton depression scale (HAMD) scores >17, 120 patients with chronic obstructive pulmonary disease (COPD) were classified into 2 groups: COPD patients with or without depression. According to the mini-mental state examination (MMSE), the cognitive functions of all patients were evaluated. Meanwhile, oxygen saturation and pulmonary function were measured by blood gas analyzer and spirometer respectively. Fifty-four COPD patients were complicated with depression. HAMD scores were significantly negatively correlated with oxygen saturation and pulmonary function (P<0.05). Multiple regression analysis revealed that gender, oxygen saturation and MMSE scores were risk factors of depression (P<0.05). MMSE scores decreased more obviously in the COPD patients with depression and were positively correlated with oxygen saturation (P<0.01). A negative correlation existed between MMSE scores and HAMD scores (r=-0.549, P<0.05). Key words: Pulmonary disease, chronic obstructive; Depression