Prevalence of Sub-threshold depression in elderly patients with chronic obstructive pulmonary disease

Objectives We hypothesized that COPD patients with sub-threshold depression would have levels of disability and impaired quality of life approaching that for major depression and significantly greater than for non-depressed COPD patients. Setting A university teaching hospital Method 137 outpatients (69 men), with a mean age of 73 years (range 60-89 years) with symptomatic irreversible, moderate to severe COPD were recruited. Subjects were interviewed using the Geriatric Mental State Schedule (GMS), a structured psychiatric interview schedule, along with its diagnostic algorithm AGECAT. A GMS/AGECAT score of 3 or more is indicative of a case-level of depression, a GMS/AGECAT score of 1-2 indicates sub-threshold depression and GMS/AGECAT of 0, no depression. Physical disability was measured by the Manchester Respiratory Activities of Daily Living questionnaire (MRADL) and quality of life was assessed by the Breathing Problems Questionnaire (BPQ). Results Mean (SD) one second forced expiratory volume was 0.89 (0.33) litres. The prevalence of GMS/AGECAT case-level depression (greater than or equal to 3) was 57 cases (42%); of GMS/AGECAT sub-threshold depression (1-2) 34 (25%); and GMS/AGECAT non-depression (0) 46 (33%). Comparison of MRADL score in the three groups (mean, 95% confidence intervals) revealed [GMS greater than or equal to 3 = 9.9 (8.4 to 11.3) vs GMS = 1-2, 12.9 (11.2 to 14.4) vs GMS = 0, 15.6 (14 to 16.6) p < 0.0001]. BPQ scores (mean, 95% confidence intervals) showed [GMS greater than or equal to 3 = 54 (50 to 57) vs GMS = 1-2, 40 (36.3 to 44) GMS = 0. 33 (30.6 to 36.7) p < 0.0001]. There was no significant difference in FEV1 between the three groups. Conclusion Sub-threshold depression accounted for 25% of the sample. In this study disability associated with sub-threshold depression in patients with COPD was intermediate to that associated with case-level depression and no with depression and significantly worse than in the latter group. Sub-threshold depression is associated with substantial morbidity in COPD. Copyright (C) 2003 John Wiley Sons, Ltd.